Comments on: Estimating the Size of a Table in SQL Server 2008 http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/ Thoughts and Code from Tim Laqua Thu, 29 Jul 2010 13:25:12 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Walter http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2903 Walter Wed, 09 Jun 2010 19:05:25 +0000 http://timlaqua.com/?p=250#comment-2903 This is great Tim. Thanks for making this calculation so much easier. This is great Tim. Thanks for making this calculation so much easier.

]]> By: Tim http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2323 Tim Thu, 19 Nov 2009 20:27:56 +0000 http://timlaqua.com/?p=250#comment-2323 Yes, you have to run it four times (once for each index). The Clustered Index needs all the columns specified, because the clustered index basically IS the table (that's why you can't have "included columns" in clustered indexes). As for the other nonclustered indexes, you only need to specify one key column for each - if you don't have any included columns in the nonclustered indexes, you don't need to have anything other than the key column(s). Also note for your non-unique nonclustered indexes, set IsClusteredIndexUnique to 0, it should really be called "IsIndexUnique". We're not really calculating the size of a table per-se because a table is simply the sum of the size of its indexes (let's not talk about heaps - there's no index there, but it certainly takes up space) - we're just calculating the size of each index. Yes, you have to run it four times (once for each index).

The Clustered Index needs all the columns specified, because the clustered index basically IS the table (that’s why you can’t have “included columns” in clustered indexes). As for the other nonclustered indexes, you only need to specify one key column for each – if you don’t have any included columns in the nonclustered indexes, you don’t need to have anything other than the key column(s). Also note for your non-unique nonclustered indexes, set IsClusteredIndexUnique to 0, it should really be called “IsIndexUnique”.

We’re not really calculating the size of a table per-se because a table is simply the sum of the size of its indexes (let’s not talk about heaps – there’s no index there, but it certainly takes up space) – we’re just calculating the size of each index.

]]> By: Oshik http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2322 Oshik Thu, 19 Nov 2009 20:15:51 +0000 http://timlaqua.com/?p=250#comment-2322 Hi Tim, i think i miss something. let me clear my request: i have a partition table with 600 million rows, with 4 indexes. one is a clustered index(three key columns) secound - non-clustered index(non uniqe, one column) third- non-clustered index(non uniqe, one column) fourth- non-clustered index(non uniqe, one column). my table has a 20 columns(varchar, int, datetime etc...). as you meen, i need to create a TYPE(and setting the isKey to 1 for eash column index) with my table definition and run it foure time? Thanks, oshik. Hi Tim,
i think i miss something.
let me clear my request:
i have a partition table with 600 million rows, with 4 indexes.
one is a clustered index(three key columns)
secound – non-clustered index(non uniqe, one column)
third- non-clustered index(non uniqe, one column)
fourth- non-clustered index(non uniqe, one column).
my table has a 20 columns(varchar, int, datetime etc…).
as you meen, i need to create a TYPE(and setting the isKey to 1 for eash column index) with my table definition and run it foure time?
Thanks,
oshik.

]]> By: Tim http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2285 Tim Mon, 16 Nov 2009 22:42:38 +0000 http://timlaqua.com/?p=250#comment-2285 For the multiple indexes, estimate each one individually. For non-clustered indexes, I just pretend it's a table and included columns are non-key columns - it seems to come out pretty close in my tests. (You can just test it out against existing indexes). As for partitioned tables and partition-aligned indexes, I've never done anything special to account for the fact that they're partitioned. As a matter of fact, all the examples I mentioned above were indeed partitioned tables and partition-aligned indexes. For the multiple indexes, estimate each one individually. For non-clustered indexes, I just pretend it’s a table and included columns are non-key columns – it seems to come out pretty close in my tests. (You can just test it out against existing indexes). As for partitioned tables and partition-aligned indexes, I’ve never done anything special to account for the fact that they’re partitioned. As a matter of fact, all the examples I mentioned above were indeed partitioned tables and partition-aligned indexes.

]]> By: Oshik http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2280 Oshik Mon, 16 Nov 2009 13:50:45 +0000 http://timlaqua.com/?p=250#comment-2280 hi TIM, how the stored procedure Utility_EstimateClusteredIndexSize know how muth indexes i have in specific table? how it's know to calculate table with six indexes(one clustered and five nonclustered index) what about partition table? Thanks, Oshik. hi TIM,
how the stored procedure Utility_EstimateClusteredIndexSize know how muth indexes i have in specific table?
how it’s know to calculate table with six indexes(one clustered and five nonclustered index)
what about partition table?
Thanks,
Oshik.

]]> By: Tim http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2236 Tim Thu, 12 Nov 2009 19:30:52 +0000 http://timlaqua.com/?p=250#comment-2236 Sure, if you can let me know what parameters you're passing to the procedure, I can take a look and try to figure out why it's not working as expected Sure, if you can let me know what parameters you’re passing to the procedure, I can take a look and try to figure out why it’s not working as expected

]]> By: vinayak http://timlaqua.com/2009/10/estimating-the-size-of-a-table-in-sql-server-2008/comment-page-1/#comment-2235 vinayak Thu, 12 Nov 2009 11:02:40 +0000 http://timlaqua.com/?p=250#comment-2235 Hi, i tried to run this. Its giving so many errors.first i executed TableColumnDefinition and theni executed the procedure.its thorowing so many exceptions. can u pls tel the way to run this? Thanks in advance. Hi,

i tried to run this. Its giving so many errors.first i executed TableColumnDefinition and theni executed the procedure.its thorowing so many exceptions. can u pls tel the way to run this?

Thanks in advance.

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