Tuesday, March 7, 2017

How to get the total row count of all SQL Server tables

I had a requirement for getting the record count of all tables in one of client databases that had many tables with over 10 millions records. There are many ways of getting this, hence explored some to find the most efficient way. I analyzed many techniques using various approaches. Here are some of the ways I used and time it took for producing the result;

  1. Using sys.partitions Catalog View - 1 second
  2. Using SELECT COUNT(*) with sp_MSforeachtable - 10 minutes
  3. Using sys.indexes and dm_db_partition_stats - 1 seconds

One thing we need to remember is, the database we have to work with can have tables with different structures. One can have a heap and another can have clustered structure. Not only that, if we use Dynamic Management Objects or objects that depend on Statistics, we may not get the accurate output. However, 1st option worked well for me, here is the code I wrote for getting result;

SELECT ROW_NUMBER() OVER(ORDER BY NofRecords) Id, TableName, TableId, NofRecords 
--INTO dbo.TableNames
 SELECT t.name TableName, t.object_id TableId, SUM(p.rows) NofRecords 
 FROM sys.partitions p
  INNER JOIN sys.tables t
   ON p.object_id = t.object_id
 WHERE p.index_id < 2 AND t.type = 'U'
 GROUP BY t.name, t.object_id) AS t;

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