📦Data Migrations (DM): Quality Assurance (Part III: Quality Acceptance Criteria III)

Data Migrations Series

Repeatability

Repeatability is the degree with which a DM can be repeated and obtain consistent results between repetitions. Even if a DM is supposed to be a one-time activity for a project, to guarantee a certain level of quality it’s important to consider several iterations in which the data requirements are refined and made sure that the data can be imported as needed into the target system(s). Considered as a process, as long the data and the rules haven’t changed, the results should be the same or have the expected level of deviation from expectations. 

This requirement is important especially for the data migrated during UAT and Go-Live, time during which the input data and rules need to remain frozen (even if small changes in the data can still occur). In fact, that’s the role of UAT – to assure that the data have the expected quality and when compared to the previous dry-run, that it attains the expected level of consistency. 

Reusability

Reusability is the degree to which the whole solution, parts of the logic or data can be reused for multiple purposes. Master data and the logic associated with them have high reusability potential as they tend to be referenced by multiple entities. 

Modularity

Modularity is the degree to which a solution is composed of discrete components such that a change to one component has minimal impact on other components. It applies to the solution itself but also to the degree to which the logic for the various entities is partitioned so to assure a minimal impact. 

Partitionability

Partitionability is the degree to which data or logic can be partitioned to address the various requirements. Despite the assurance that the data will be migrated only once, in practice this assumption can be easily invalidated. It’s enough to increase the system freeze by a few days and/or to have transaction data that suddenly requires master data not considered. Even if the deltas can be migrated in system manually, it’s probably recommended to migrate them using the same logic. Moreover, the performing of incremental loads can be a project requirement. 

Data might need to be partitioned into batches to improve processing’s performance. Partitioning the logic based on certain parameters (e.g. business unit, categorical values) allows more flexibility in handling other requirements (e.g. reversibility, performance, testability, reusability). 

Performance

Performance refers to the degree a piece of software can process data into an amount of time considered as acceptable for the business. It can vary with the architecture and methods used, respectively data volume, veracity, variance, variability, or quality.

Performance is a critical requirement for a DM, especially when considering the amount of time spent on executing the logic during development, tests and troubleshooting, as well for other activities. Performance is important during dry-runs but more important during Go-Live, as it equates with a period during which the system(s) are not available for the users. Upon case, a few hours of delays can have an important impact on the business. In extremis, the delays can sum up to days. 

Predictability

Predictability is the degree to which the results and behavior of a solution, respectively the processes involve are predictable based on the design, implementation or other factors considered (e.g. best practices, methodology used, experience, procedures and processes). Highly predictable solutions are desirable, though reaching the required level of performance and quality can be challenging. 

The results from the dry-runs can offer an indication on whether the data migrated during UAT and Go-Live provide a certain level of assurance that the DM will be a success. Otherwise, an additional dry-run should be planned during UAT, if the schedule allows it.

Previous Post <> Nest Post 

📦Data Migrations (DM): Quality Assurance (Part II: Quality Acceptance Criteria II)

Data Migrations Series

Auditability

Auditability is the degree to which the solution allows checking the data for their accuracy, or for their quality in general, respectively the degree to which the DM solution and processes allow to be audited regarding compliance, security and other types of requirements. All these aspects are important in case an external sign-off from an auditor is mandatory. 

Automation

Automation is the degree to which the activities within a DM can be automated. Ideally all the processes or activities should be automated, though other requirements might be impacted negatively. Ideally, one needs to find the right balance between the various requirements. 

Cohesion

Cohesion is the degree to which the tasks performed by the solution, respectively during the migration, are related to each other. Given the dependencies existing between data, their processing and further project-related activities, DM imply a high degree of cohesion that need to be addressed by design. 

Complexity 

Complexity is the degree to which a solution is difficult to understand given the various processing layers and dependencies existing within the data. The complexity of DM revolve mainly around the data structures and the transformations needed to translate the data between the various data models. 

Compliance 

Compliance is the degree to which a solution is compliant with internal or external regulations that apply. There should be differentiated between mandatory requirements, respectively recommendations and other requirements.

Consistency 

Consistency is the degree to which data conform to an equivalent set of data, in this case the entities considered for the DM need to be consistent to each other. A record referenced in any entity of the migration need to be considered, respectively made available in the target system(s) either by parametrization or migration. 

During each iteration, the data need to remain consistent, so it can facilitate the troubleshooting. The data are usually reimported between iterations or during same iteration, typically to reflect the changes occurred in the source systems or other purposes. 

Coupling 

Data coupling is the degree to which different processing areas within a DM share the same data, typically a reflection of the dependencies existing between the data. Ideally, the areas should be decoupled as much as possible. 

Extensibility

Extensibility is the degree to which the solution or parts of the logic can be extended to accommodate further requirements. Typically, this involves changes that deviate from the standard functionality. Extensibility impacts positively the flexibility.

Flexibility 

Flexibility is the degree to which a solution can handle new requirements or ad-hoc changes to the logic. No matter how good everything was planned there’s always something forgotten or new information is identified. Having the flexibility to change code or data on the fly can make an important difference. 

Integrity 

Integrity is the degree to which a solution prevents the changes to data besides the ones considered by design. Users and processes should not be able modifying the data besides the agreed procedures. This means that the data need to be processed in the sequence agreed. All aspects related to data integrity need to be documented accordingly. 

Interoperability 

Interoperability is the degree to which a solution’s components can exchange data and use the respective data. The various layers of a DM’s solutions must be able to process the data and this should be possible by design. 

Maintainability

Maintainability is the degree to which a solution can be modified to or add minor features, change existing code, corrects issues, refactor code, improve performance or address changes in environment. The data required and the transformation rules are seldom known in advance. The data requirements are definitized during the various iterations, the changes needing to be implemented as the iterations progress. Thus, maintainability is a critical requirement.

Previous Post - Next Post

📦Data Migrations (DM): Quality Assurance (Part I: Quality Acceptance Criteria I)

Data Migrations Series

Introduction

When designing a Data Migration (DM), respectively any software solution, it’s important to take inventory of project’s requirements, evaluate, document, communicate and monitor them accordingly. Each of them can have an important impact on the solution, as a solution’s success will be validated and judged upon them. Therefore, the identified requirements must be considered as baseline for conceptualization, design, implementation and sign-off, and should go through same procedures and rigor as other projects requirements. The existence of a standardized Requirements Management process can facilitate their management through project’s lifecycle. 

The requirements are usually driven by the source and target systems (e.g. data import/export features, data models and their constraints), the environments they are hosted on (e.g. cloud vs. on-premise), respectively the layers in between (e.g. network, firewalls), project and business aspects that need to be considered (e.g. freeze window for the Go-Live, data availability dates, data quality, external dependencies, etc.). They resume to the solution itself as well to the data and processes involved, and are reflected but not limited to the following important aspects, that can be considered upon case also as quality acceptance criteria: 

Accessibility

Accessibility is the degree to which the data are available for a solution so it can be processed when needed, in the form, by resources, or means intended for processing. It’s critical for a DM solution to access or have available the master, transaction, parameter and further data when needed. The team must make sure that the data become easily accessible. 

Unavailability of data can impact the DM and can easily lead to delays in the project. This also means that the various project activities (parametrization, cleansing, enrichment, development) need to be synchronized with the migration activities. 

Upon case, accessibility can involve the solution itself expressed as the degree to which it’s available to the resources supposed to use it. Certain architectural decisions can have impact on the carried activities. As the solution is usually deployed on a server, it can happen that only a limited number of people is able to access it concurrently. Moreover, a DM’s complexity makes the involvement of multiple developers challenging.  

Accountability

Accountability is the degree to which accountability is enforced for the various resources involved in DM processes and related activities. As multiple resources are involved for parametrization, cleaning, processing, validation, software development, each resource needs to be aware about the extent they are accountable for. Without accountability made explicit, there’s the danger that the activities are neglected, with all the implications deriving from it – quality deviations, delays, data unavailability, etc. 

Adaptability

Adaptability is the degree to which a solution can be adapted to environment or requirement changes. Even if typically, the environments don’t change, it doesn’t mean that this will not happen as the IT infrastructure goes through continuous changes that can affect directly or indirectly a migration.  Same can be said about requirements, which however have higher probability to change even late in the process as new knowledge is acquired and needs to be integrated in the solution. 

Atomicity 

Atomicity is the degree to which data entities can be processes at the required level of abstraction in an atomic manner. Even if transformations occur during the various stages, the data belonging to an entity need to be kept and processed together (e.g. Customers and their Addresses). This can involve processing attributes in advance even if the data might be required later. There can be situations in which the data belonging to the same entity need to be processed on different paths, though in the end it’s important to keep the data together, when the processing logic allows it. 

Next Post

💎💫SQL Reloaded: D365FO Security Queries

The security architecture of Microsoft Dynamics 365 for Finance and Operations (D365FO) is based on a role-based model in which the access is not granted individually to users but through security roles. A set of roles are assigned to a user, each role having access to a set of privileges. In between duties can be assigned to one or more roles, respectively duties can contain several privileges. The model comes with a default set of security roles, which can be further extended to reflect organization's needs. 

Navigating through the model via the D365FO's UI isn't that straightforward as it should be. Probably it's much easier to export to Excel the associations between roles and privileges, respectively between roles and duties, or search punctually for a certain value within the same dataset directly in the database. The following queries can be run into a non-production environment:

-- security role's assigned privileges
SELECT SRO.AOTName [Role AOT Name]
, SRO.Name [Role Name]
, SRO.Description [Role Description]
, SPI.Identifier [Privilege Identifier]
, SPI.Name [Privilege Name]
, SPI.Description [Privilege Description]
FROM dbo.SecurityRolePrivilegeExplodedGraph SRP
     JOIN dbo.SecurityRole SRO
          ON SRP.SecurityRole = SRO.RecId
         JOIN dbo.SecurityPrivilege SPI
           ON SRP.SecurityPrivilege = SPI.RecId
WHERE SPI.NAME IN ('Maintain accounts receivable aging period definitions'
, 'Maintain accounts payable aging period definitions')
ORDER BY SRO.AOTName

-- security role's assigned duties
SELECT  SRO.AOTName [Role AOT Name]
, SRO.Name [Role Name]
, SRO.Description [Role Description]
, SDU.Identifier [Duty Identifier]
, SDU.Name [Duty Name]
, SDU.Description [Duty Description]
FROM dbo.SecurityRoleDutyExplodedGraph SRP
     JOIN dbo.SecurityRole SRO
          ON SRP.SecurityRole = SRO.RecId
        JOIN dbo.SecurityDuty SDU
          ON SRP.SecurityDuty = SDU.RecId
WHERE SRO.Name LIKE 'Accounting Manager%'
ORDER BY SDU.Identifier 

Below you can find a short description of the security tables considered above:

Table	Description
SecurityDuty	contains the list of duties defined by the security AOT role node
SecurityPrivilege	contains the list of privileges defined by the security AOT role node
SecurityRole	contains the list of roles defined by the security AOT role node
SecurityRoleDutyExplodedGraph	contains the list of role to duty mappings and role to privilege mappings as defined by the AOT security role
SecurityRoleExplodedGraph	contains all role relationships, direct or indirect, as defined by the AOT sub role nodes of the security role nodes.
SecurityRolePrivilegeExplodedGraph	contains the list of role to privilege mappings and role to privilege mappings as defined by the AOT security role
SecurityUserRole	contains the user to role mappings

Resources:
[1] Microsoft Dynamics 365 (2020) Security architecture [source]
[2] Microsoft Dynamics 365 (2020) Role-based security [source]

💎💫SQL Reloaded: Useful Queries for D365 FO (and not only)

Microsoft Dynamics 365 for Finance and Operations (D365 FO or simply D365) has currently more than 12000 tables, therefore attempting to understand the data model behind might seem at first sight to be a foolhardy effort. Fortunately, only a small percentage from all the tables contain meaningful master or transactional data, fact that makes easier the task. 

Moreover, the tables have meaningful prefixes (e.g. 'Invent' for Inventory, 'Purch' for Purchae Orders, 'Sales' for Sales Orders, etc.) and postfixes (e.g. 'Table for header data, 'Line' for position data, 'Trans' for transaction data) while their names are in many cases self-explanatory if one knows the corresponding business terms.

For those coming from earlier versions of D365 (e.g. Microsoft Dynamics AX 2009), with a few exceptions in the inventory transactions, product master data, addresses and finance dimensions, the data structures remained almost the same, if one considers the main functional area of the ERP system. However as new modules and/or functionality were added, the number of new tables increased considerably between the versions. 

On the other side in D365 the data are exposed through data entities, abstractions from the physical implementation of the database tables [1], implemented as views typically having the 'Entity' postfix. In many scenarios the data entities more likely will prove to be the best way of accessing the data, as they include an important part of the logic one will need anyway to reengineer, however there are maybe also exceptions in which is needed to work with the base tables. In the end it will be needed to know the main data entities as well the important tables related to them, being needed to check which views reference a given table, respectively which tables are references by a view. This can be easily achieved via the sys.sql_expression_dependencies system catalog view. 

The following queries can be run in non-production D365 environments:

-- retrieving the views where an object was used 
SELECT SCHEMA_NAME(obj.SCHEMA_ID) + '.'+ obj.name AS ReferencingObject
, obj.type_desc
, SCHEMA_NAME(obj.SCHEMA_ID) + '.'+ sed.referenced_entity_name AS ReferencedObject
, obr.type_desc ReferencedObjectType
FROM sys.all_objects obj
     JOIN sys.sql_expression_dependencies sed 
       ON obj.OBJECT_ID = sed.REFERENCING_ID 
	      JOIN sys.all_objects obr
		    ON sed.referenced_id = obr.object_id
WHERE sed.referenced_entity_name = 'PurchTable'
  AND obj.Type = 'V'
  AND obj.name LIKE 'Purch%'
ORDER BY ReferencingObject

Output (12 records):

ReferencingObject	type_desc	ReferencedObject	ReferencedObjectType
dbo.PURCHASEORDERCUBE	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHASEORDERRESPONSEHEADERSUMMARY	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHLINEBACKORDER	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHLINEBACKORDERWORKSPACE	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHLINEEXPANDED	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHORDERAPPROVEDVIEW	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHPREPAYOPENBASE	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERCHARGEENTITY	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERENTITY	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHPURCHASEORDERLINECDSENTITY	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHTABLENOTARCHIVEDVERSIONS	VIEW	dbo.PURCHTABLE	USER_TABLE

The inverse search: 

-- retrieving the objects referenced in a view
SELECT SCHEMA_NAME(obj.SCHEMA_ID) + '.'+ obj.name AS ReferencingObject
, obj.type_desc ReferncingObjectType
, SCHEMA_NAME(obj.SCHEMA_ID) + '.'+ sed.referenced_entity_name AS ReferencedObject
, obr.type_desc ReferencedObjectType
FROM sys.all_objects obj
     JOIN sys.sql_expression_dependencies sed 
       ON obj.OBJECT_ID = sed.referencing_id 
	      JOIN sys.all_objects obr
		    ON sed.referenced_id = obr.object_id
WHERE obj.name = 'PURCHPURCHASEORDERHEADERV2ENTITY'
ORDER BY ReferencedObject

Output:

ReferencingObject	ReferncingObjectType	ReferencedObject	ReferencedObjectType
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.ACCOUNTINGDISTRIBUTIONTEMPLATE	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.CONFIRMINGPO	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.DIMENSIONSETENTITY	VIEW
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.GetValidFromInContextInfo	SQL_SCALAR_FUNCTION
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.GetValidToInContextInfo	SQL_SCALAR_FUNCTION
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.HCMWORKER	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.LOGISTICSPOSTALADDRESS	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.LOGISTICSPOSTALADDRESSBASEENTITY	VIEW
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.PURCHTABLE	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.PURCHTABLE_W	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.REASONTABLEREF	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.TMSPURCHTABLE	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.TRANSPORTATIONDOCUMENT	USER_TABLE
dbo.PURCHPURCHASEORDERHEADERV2ENTITY	VIEW	dbo.VENDINVOICEDECLARATION_IS	USER_TABLE

Notes:

1. There will be cases in which is needed to check views' definition. To understand the logic it will be needed to format the queries in a more readable form. This can take time, given that the joins and the further constraints are not always straightforward. Therefore, it might be a good idea to export a formatted copy of the view for later use.

2.  Unfortunately, the data model for D365 is not publicly available. One can use however the data model for AX 2012 (see [2] [3]) as basis and fill the gaps when needed. 

3. The important changes between the various data models versions are partially documented in several documents available via the Microsoft Dynamics CustomerSource. 

4. For non-production environments the data from views, tables or other database objects can be exported directly from the database. Unfortunately, Microsoft blocked the direct access to production environments. The data from tables can be accessed and exported via the table browser, while the data from entities can be exported to Excel typically from the display forms or via the Data Management Framework.

5. The queries can be used to explore any SQL Server database. The logic can be easily encapsulated in a view to simplify the calls. 

References:
[1] Microsoft Dynamics 365 (2020) Data entities overview [source]

[2] Microsoft Docs (2014) Application tables [source]

[3] Microsoft Docs (2014) Base Enums AX 2012 [source]

💠🛠️SQL Server: Undocumented (Part IV: DBCC SQLPERF)

Besides the documented LOGSPACE parameter (see previous post), DBCC SQLPERF utility has several undocumented parameters which allow providing statistics about schedulers, threads, spinlocks, IO, network, read-aheads, respectively waits.  

Scheduler Statistics

By providing 'umsstats' as parameter, the utility returns as result the visible UMS schedulers on the system:

-- visible UMS schedulers
DBCC SQLPERF(umsstats)

Output:

Statistic	Value
Node Id	0
Avg Sched Load	5
Sched Switches	6903
Sched Pass	6721358
IO Comp Passes	11334
Scheduler ID	0
online	1
num tasks	6
num runnable	0
num workers	9
active workers	6
work queued	0
cntxt switches	7125444
cntxt switches(idle)	9898903
preemptive switches	2304
Scheduler ID	1
online	1
num tasks	6
num runnable	0
num workers	9
active workers	5
work queued	0
cntxt switches	3370432
cntxt switches(idle)	4427991
preemptive switches	22729

The fields have the following meaning: 

Statistic	Description
Node Id
Avg Sched Load
Sched Switches	The number of switches between schedulers
Sched Pass
IO Comp Passes
Scheduler ID	The scheduler's zero-based ID number
num tasks	The number of tasks associated with the scheduler
num runnable	The number of workers on the runnable list
num workers	The total number of workers associated with the scheduler
idle workers	The number of idle workers
work queued	The number of items waiting to be processed in the work queue
cntxt switches	The number of switches between workers for the scheduler
cntxt switches(idle)	The number of times the idle loop was switched into

The functionality is useful when one suspects that there are issues related to the visible schedulers.

Detailed information about the schedulers can be found also via the sys.dm_os_schedulers DMV.

Threads Statistics

By providing 'threads' as parameter, the utility returns as result the threads created in the system:

--  thread statistics
DBCC SQLPERF(threads)

Output (just the first records):

Spid	Thread ID	Status	LoginName	IO	CPU	MemUsage
1	11228	background	sa	0	0	0
2	12572	background	sa	0	0	0
3	12576	background	sa	0	0	0
4	11884	background	sa	0	0	0
5	12964	background	sa	0	0	0
6	12960	background	sa	0	0	4
7	12968	background	sa	0	0	0

Detailed information about the schedulers can be found also via the sys.dm_os_threads DMV.

IO Statistics

By providing 'iostats' as parameter, the utility returns as result a count of the outstanding reads, respectively writes:

--  IO statistics
DBCC SQLPERF(iostats)

Output:

Statistic	Value
Reads Outstanding	0
Writes Outstanding	0

Network Statistics

By providing 'netstats' as parameter, the utility returns as result network-related statistics:

--  network statistics
DBCC SQLPERF(netstats)

Output:

Statistic	Value
Network Reads	6976
Network Writes	9036
Network Bytes Read	5318957
Network Bytes Written	2,222512E+07
Command Queue Length	0
Max Command Queue Length	0
Worker Threads	0
Max Worker Threads	0
Network Threads	0
Max Network Threads	0

Read Ahead Statistics

By providing 'rastats' as parameter, the utility returns read-ahead statistics:

--  read ahead statistics
DBCC SQLPERF(rastats)

Output

Statistic	Value
RA Pages Found in Cache	0
RA Pages Placed in Cache	0
RA Physical IO	0
Used Slots	0

Spinlock Statistics

By providing 'spinlockstats' as parameter, the utility returns the spinlock statistics, where a spinlock is a a lightweight synchronization object used to serialize access to data structures which are typically held for a short period of time:

--  spinlock statistics
DBCC SQLPERF(spinlockstats)

Output:

Spinlock Name	Collisions	Spins	Spins/Collision	Sleep Time (ms)	Backoffs
LOCK_RW_TEST	0	0	0	0	0
LOCK_RW_SECURITY_CACHE	711	210500	296,0619	0	54
LOCK_RW_CMED_HASH_SET	5	1750	350	0	1
LOCK_RW_ABTX_HASH_SET	0	0	0	0	0
LOCK_RW_RBIO_REQ	0	0	0	0	0

Detailed information about the spinlock stats can be found also via the sys.dm_os_spinlock_stats DMV.

Wait Statistics

By providing 'waitstats' as parameter, the utility returns the available wait statistics:

-- wait statistics 
DBCC SQLPERF(waitstats)

Output (only a few records):

Wait Type	Requests	Wait Time	Signal Wait Time
LCK_M_SCH_M	18	597	3
LCK_M_S	13	16895	0
PAGEIOLATCH_SH	1789	38568	25
PAGEIOLATCH_UP	118	101	0
PAGEIOLATCH_EX	736	10490	16

Detailed information about the wait stats can be found also via sys.dm_os_wait_stats DMV.

Notes:
As Microsoft warns, the undocumented features shouldn't be used into production environments as they will be deprecated in future versions. Instead should be used the documented DMVs, when available. 
All objects mentioned above require VIEW SERVER STATE permissions.
The DBCC SQLPERF utility allows resetting the latch, spinlock, respectively the wait statistics by providing the following parameters (see the SQL Docs for more information): 

-- resetting the latch statistics
DBCC SQLPERF('sys.dm_os_wait_stats', CLEAR)

-- resetting the spinlock statistics
DBCC SQLPERF ('sys.dm_os_spinlock_stats', CLEAR);  

-- resetting the wait statistics
DBCC SQLPERF('sys.dm_os_latch_stats', CLEAR)

DBCC PERFMON provides in a single call the IO, network, read ahead, spinlocks, respectively the wait statistics in distinct resultsets:

-- performance statistics
DBCC PERFMON

🔏MS Office: Excel for SQL Developers V (Formatting Output to HTML)

Some years back I found a tool to format the SQL and VB.Net code in posts (see hilite.me), tool which made blogging much easier, as I didn't had to format the code manually myself. However, showing the output of the queries into blog posts resumed mainly to making screenshots, which is unproductive and wastes space from my quota. Therefore, today I took the time to create a small Excel macro which allows formatting an MS Excel range to a HTML table. The macro is pretty basic, looping though range's cells:

'formats a range as html table
Public Function GetTable(rng As Range)
  Dim retval As String
  Dim i, j As Long
  
  retval = "<table style=""width: 90%;color:black;border-color:black;font-size:10px;"" border=""0"" cellpadding=""1"">"
  
  For i = 1 To rng.Rows.Count()
    retval = retval & "<tr style=""background-color:" & IIf(i = 1, "#b0c4de", "white") & ";font-weight:" & IIf(i = 1, "bold", "normal") & """>"
    
    For j = 1 To rng.Columns.Count()
       retval = retval & "<td align=""" & IIf(IsNumeric(rng.Cells(i, j)), "right", "left") & """>" & rng.Cells(i, j) & "</td>"
    Next
    
    retval = retval & "</tr>" & vbCrLf
  Next
  
  retval = retval & "</table>"
  
  GetTable = retval
End Function

Just copy the GetTable macro into a new module in Excel and provide the range with data as parameter.

 Unfortunately, copying macro's output to a text file introduces two double quotes where just one was supposed to be:

This requires as intermediary step to replace the two double quotes with one in Notepad (e.g. via the Replace functionality), respectively to remove manually the first and last double quotes. 

Notes:
1. Feel free to use and improve the macro. 
2. Further formatting can be added afterwards as seems fit. 

Happy coding!

💠🛠️SQL Server: Administration (Monitoring the Database Logs)

One of the aspects to monitor on a SQL Server instance is the size of the logs available for each database, respectively the degree to which the logs are used. Starting with SQL Server 2005 this could be achieved by using the 'Log File(s) Used Size (KB)' and 'Log File(s) Size (KB)'  counters via the sys.dm_os_performance_counters DMV as follows:

-- log files - size (kb)
SELECT lfu.instance_name database_name
, lfu.cntr_value size_kb
, Cast(lfu.cntr_value/1024.00 as decimal (18,2)) size_MB
FROM sys.dm_os_performance_counters lfu 
WHERE lfu.counter_name LIKE  'Log File(s) Size (KB)%' 
  AND lfu.object_name LIKE 'SQLServer:Databases%'
  AND lfu.instance_name IN ('tempdb', 'master', 'model', 'msdb')
ORDER BY lfu.instance_name

-- log files - used size (kb)
SELECT lfs.instance_name database_name
, lfs.cntr_value used_size_kb
, Cast(lfs.cntr_value/1024.00 as decimal (18,2)) used_size_MB
FROM sys.dm_os_performance_counters lfs
WHERE lfs.counter_name LIKE  'Log File(s) Used Size (KB)%' 
  AND lfs.object_name LIKE 'SQLServer:Databases%'
  AND lfs.instance_name IN ('tempdb', 'master', 'model', 'msdb')
ORDER BY lfs.instance_name

The two queries can be combined into one as follows:

-- database log space allocation (SQL Server 2005+)
SELECT db.name database_name
, db.log_reuse_wait_desc 
, Cast(lfs.cntr_value/1024.00 as decimal(28,2)) size_MB
, Cast(lfu.cntr_value/1024.00 as decimal(28,2)) AS used_MB
, Cast(100.00*lfu.cntr_value/lfs.cntr_value as decimal(10,2)) used_percent 
, CASE WHEN CAST(lfu.cntr_value AS float) / CAST(lfs.cntr_value AS float) > .5 THEN 
   CASE 
    WHEN db.name = 'tempdb' AND log_reuse_wait_desc NOT IN ('CHECKPOINT', 'NOTHING') THEN 'WARNING'  
    WHEN db.name <> 'tempdb' THEN 'WARNING' 
    ELSE 'OK' 
    END 
  ELSE 'OK' END log_status 
FROM sys.databases db 
     JOIN sys.dm_os_performance_counters lfs 
       ON db.name = lfs.instance_name 
      AND lfs.counter_name LIKE 'Log File(s) Size (KB)%' 
     JOIN sys.dm_os_performance_counters lfu 
       ON db.name = lfu.instance_name 
      AND lfu.counter_name LIKE  'Log File(s) Used Size (KB)%' 
WHERE db.name IN ('tempdb', 'master', 'model', 'msdb')
ORDER BY db.name 

Output:

database_name	log_reuse_wait_desc	size_MB	used_MB	used_percent	log_status
master	NOTHING	1.99	1.11	55.78	WARNING
model	NOTHING	7.99	1.74	21.80	OK
msdb	NOTHING	28.80	1.96	6.81	OK
tempdb	NOTHING	999.99	0.69	0.07	OK

Starting with SQL Server 2012 the same information can be obtained via the sys.dm_db_log_space_usage DMV, however the view returns information only for the current database:

-- getting the log space only for a database (SQL Server 2012+)
SELECT db_name(database_id) database_name 
, Cast(total_log_size_in_bytes/1024.00/1024.00 as decimal(28,2)) size_MB
, Cast(used_log_space_in_bytes/1024.00/1024.00 as decimal(28,2)) used_MB
, Cast(used_log_space_in_percent as decimal(28,2)) used_percent
FROM sys.dm_db_log_space_usage

Output:

database_name	size_MB	used_MB	used_percent
master	1.99	1.19	59.61

With less flexibility one can obtain the size in MB and the used percentage by using the DBCC utility as follows:

-- retrieving the log usage for all databases
DBCC SQLPERF(LOGSPACE); 

Output:

Database Name	Log Size (MB)	Log Space Used (%)	Status
master	1,992188	33,13726	0
tempdb	999,9922	0,06352589	0
model	7,992188	21,11437	0
msdb	28,80469	6,617846	0
AdventureWorks2014	33,99219	14,76672	0
AdventureWorksDW2014	17,99219	22,6878	0

Notes:
1. All the mentioned objects require VIEW SERVER STATE permissions.
2. The solution based on the performance counters returns slightly different values than the other solutions, though the differences are neglectable. 

Resources: 
[1] SQL Docs (2017) sys.dm_os_performance_counters [source]
[2] SQL Docs (2017) DBCC SQLPERF [source]
[3] SQL Docs (2017) sys.dm_db_log_space_usage [source]

🧮ERP: Panning (Part I: It’s all about Planning - An Introduction)

Ideally the total volume of work can be uniformly distributed for all project’s duration though in praxis the curve representing the effort has the form of a wave or aggregation of waves that tend to reach the peak shortly before or during the Go-Live(s). More important, higher fluctuations occur in the various areas of the project on whole project’s duration, as there are dependencies between the various functional areas, as one needs to wait for decisions to be made, people are not available, etc. Typically, the time wasted on waiting, researching or other non-value-added activities have the potential of leading to such peaks. Therefore, the knowledge must be available, and decisions must be taken when required, which can be challenging but not impossible to achieve. 

To bridge the time wasted on waiting, the team members need to work on other topics. If on customer’s side the resources can handle maybe other activities, on vendor’s side the costs can be high and proportional with the volume of waiting. Therefore, vendor’s resources must be involved at least in two projects or do work in other areas in advance, which is not always possible. However, when vendor’s resources are involved in two or more projects, unless the planning is perfect or each resource can handle the work as it comes, there are further waiting times added. The customer is then forced either to book the resources exclusively, or to wait and carry the costs associated with it. 

On the other side ERP Implementations tend to become exploration projects, especially when the team has only partial knowledge about the system, or the requirements have a certain degree of specialization that deviates from the standard processes. The more unknowns an ERP implementation has, the more difficult is to plan. To be able to plan one must know the activities ahead, how long they take, and of course, one must adhere to the delivery dates, because each delay can have a cascading effect that can impact project’s schedule considerably. 

Probably the best approach to planning is to group the activities into packages and plan the packages, being in each subteam’s duty to handle the planning for each package, following to manage at upper level only the open issues, risks or opportunities. This shifts the burden from Project Manager’s shoulders within the project. Moreover, even if in theory the plan can consider each activity, it will become obsolete as soon it’s updated given the considerable volume of work requested to maintain it. Periodically, one can still revise the whole plan to identify opportunities and risks. What the team can do is to plan for a certain time interval (e.g. 4-6 weeks) and build from there. This allows focusing on the most important activities. 

To further shift the burden, activities like Data Migration, Data Cleaning or the integrations with third party systems should be treated when possible as subprojects. Despite having interdependencies with the main project (e.g. parameters, master data, decisions) and share same resources, they have their own schedule whose deadlines need to be aligned with main project’s milestones. 

Unless the team and business put all effort to respect the plan and, as long the plan is realistic, the initial plan can seldom be respected – it’s anyway just a sketch of the road ahead that can change as the project progresses – and this aspect needs to be understood by the business otherwise will lead to false expectations. On the other side, the team must try respecting the deadlines and communicate in time inability to do so. It’s an interplay in which communication is more important than ever.

Previous Post <<||>> Next Post

🧮ERP: Planning (Part I: It’s all about Partnership - An Introduction)

ERP Implementations Series

Unless the organization (customer) implementing an ERP system has a strong IT team and the knowledge required for the implementation is available already in-house, the resources need to be acquired from the market, and probably the right thing to do is to identify a certified implementer (partner) which can fill the knowledge and skillset gaps, respectively which can help splitting the risks associated with such an implementation.

In theory, the customer provides knowledge about its processes, while the partner comes with expertise about the system to be implemented and further technologies, industry best practices, project methodologies, etc. Further on, the mix is leveraged to harness the knowledge and reach project’s objectives. 

In praxis however finding an implementer which can act as partner might be more challenging than expected. This because the implementer needs to understand customer’s business and where it’s heading, bridge the gap between functional requirements and system’s functionality, advise on areas of improvement, prepare the customer for the project and lead the customer through the changes, respectively establish a basis for the future. Some of the implications are seldom made explicit even if they are implied by what is needed by the project. 

Technology is seldom the issue in an ERP implementation, the challenges residing in handing the change and the logistics required. There are so many aspects to be considered and handled, and this can be challenging for any implementer no matter how long has been on the market or how experienced the resources are. Somebody needs to lead the change and the customer seldom has the knowledge to handle the change. In some cases, the implementer must make the customer aware of the implications, while in others needs to take the initiative and lead the change, though the customer needs to play along, which can be challenging also. 

Many aspects need to be handled at management level from a strategical point of view on customer’s side. It starts with assuring that the most important aspects of the business where considered, that the goals and objectives are clear, that the proper environment is created, and ends with the timely decision-making, with assuring that the resources are available when needed, that the needed organization structures and roles are in place, that the required knowledge is available before, during and after implementation, that the potential brought by the ERP system is harnessed for the years to come. 

A partnership allows in theory splitting the implementation risks as ERP implementations have a high rate of failure. Quite often the outcomes of such projects don’t meet the expectations, the systems being in extremis unusable or a bottleneck for the organization. Ideally one should work with the partner(s) and attempt solving the issues, split eventually the incurred cost overruns, find a middle way. Most of the times it’s recommended to find a solution together rather than coming to a litigation. 

Given the complex dependencies existing between the various parts of the project, the causes that lead to poor implementations are difficult to prove, as there are almost always grey areas. Moreover, the litigations can require a considerable time and resources to settle. These can be just extreme situations, and as long one has a good partner, there’s no need to think that far. On the other side, even if undesirable, one must be prepared also for such outcomes, even if the countermeasures may involve an additional effort. Therefore, one must address such issues in contracts by establishing the areas of accountability/responsibilities for each party, document adequately the requirements and further (important) communication, make sure that the deliverables have the expected quality, etc.

Previous Post <<||>> Next Post