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Questions about temporary tables in SQL Azure

  • June 15, 2011 at 6:56 pm

    #242124

    I've been doing some research into how temporary tables work in SQL Azure, and I have a few questions that I can't find answers for.

    My questions:

    1. Can you build a local temp table with a user-defined data type?

    2. Can you build a local temp table with a user-defined function?

    3. Can you build a local temp table with named constraints?

    4. Is the collation of local temp tables that of tempdb, or of the current database?

    5. Are the object_id values for local temp tables positive or negative?

    6. Is the local temp table built in tempdb, or the current database?

    Note that most of these are things that change when using a contained database in Denali, and I suspect that some of these are also changed in Azure.

    Thanks!

    Edit: and if you happen to have a link that documents any of these, that would be most excellent!

    Wayne
    Microsoft Certified Master: SQL Server 2008
    Author - SQL Server T-SQL Recipes

    If you can't explain to another person how the code that you're copying from the internet works, then DON'T USE IT on a production system! After all, you will be the one supporting it!
    Links:
    For better assistance in answering your questions
    Performance Problems
    Common date/time routines
    Understanding and Using APPLY Part 1 & Part 2

  • June 17, 2011 at 9:21 am

    #1340524

    WayneS (6/15/2011)

    I've been doing some research into how temporary tables work in SQL Azure, and I have a few questions that I can't find answers for.

    My questions:

    1. Can you build a local temp table with a user-defined data type?

    nope

    2. Can you build a local temp table with a user-defined function?

    Nope, nope

    3. Can you build a local temp table with named constraints?

    Yep, that works.

    4. Is the collation of local temp tables that of tempdb, or of the current database?

    Not sure, how the heck do you check?

    5. Are the object_id values for local temp tables positive or negative?

    Positive for the one I tested.

    6. Is the local temp table built in tempdb, or the current database?

    Based on the query I had to run to get the object_id, it's in tempdb.

    Note that most of these are things that change when using a contained database in Denali, and I suspect that some of these are also changed in Azure.

    Thanks!

    Edit: and if you happen to have a link that documents any of these, that would be most excellent!

    Hope that helps. I got most of them.

    "The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
    - Theodore Roosevelt

    Author of:
    SQL Server Execution Plans
    SQL Server Query Performance Tuning

  • June 17, 2011 at 8:40 pm

    #1340751

    Awesome Grant! Thank you very much!!!

    Grant Fritchey (6/17/2011)

    WayneS (6/15/2011)

    I've been doing some research into how temporary tables work in SQL Azure, and I have a few questions that I can't find answers for.

    My questions:

    1. Can you build a local temp table with a user-defined data type?

    nope

    2. Can you build a local temp table with a user-defined function?

    Nope, nope

    3. Can you build a local temp table with named constraints?

    Yep, that works.

    4. Is the collation of local temp tables that of tempdb, or of the current database?

    Not sure, how the heck do you check?

    Hmm, good question. In Azure you can't access tempdb, so I've got no idea of how to test this out.

    5. Are the object_id values for local temp tables positive or negative?

    Positive for the one I tested.

    6. Is the local temp table built in tempdb, or the current database?

    Based on the query I had to run to get the object_id, it's in tempdb.

    I assume your query was something like SELECT OBJECT_ID('tempdb..#table')?

    Note that most of these are things that change when using a contained database in Denali, and I suspect that some of these are also changed in Azure.

    Thanks!

    Edit: and if you happen to have a link that documents any of these, that would be most excellent!

    Hope that helps. I got most of them.

    It helps a lot. You went above and beyond what I had asked you about earlier, so I thank you very much!

    Okay, so in recap:

    UDDT: Regular SQL: Yes; Denali: No in contained databases; Azure: No

    UDF: Regular SQL: Yes; Denali: No in contained databases; Azure: No

    Named constraints: Regular SQL: Yes; Denali: No in contained databases; Azure: Yes

    Collation: Regular SQL: tempdb; Denali: Local DB in contained databases; Azure: ?

    Local temp table object_id values: SQL <= 2008R2: Positive; Denali: Negative; Azure: Positive

    Local temp table built in tempdb?: Yes

    Global Temp Tables: Regular SQL: Allowed; Denali: Allowed; Azure: Denied

    Wayne
    Microsoft Certified Master: SQL Server 2008
    Author - SQL Server T-SQL Recipes

    If you can't explain to another person how the code that you're copying from the internet works, then DON'T USE IT on a production system! After all, you will be the one supporting it!
    Links:
    For better assistance in answering your questions
    Performance Problems
    Common date/time routines
    Understanding and Using APPLY Part 1 & Part 2

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