Insufficient Disk Space

The SAP Sybase IQ server does not wait for additional space on an out-of-dbspace condition, but rolls back either the entire transaction or rolls back to a savepoint.

If there is not enough temporary or main dbspace available for a buffer or dbspace allocation request, the statement making the request rolls back.

At this point, the DBA can add more space to a dbspace using the ALTER DBSPACE or the ALTER FILE command. (You may choose to add files instead of dbspaces. A single dbspace can have multiple dbfiles.)

Warning!  If SAP Sybase IQ holds certain system locks or is performing a checkpoint when you run out of disk space, you may not be able to add disk space. It is important for you to recognize when you are low on disk space, and to add a new dbspace before you run out of space.

Actions

  • Check recent messages in the SAP Sybase IQ message log (dbname.iqmsg). An out of space message indicates that you must add another dbspace. The message in the SAP Sybase IQ message file indicates which dbspace has run out of space. If the problem occurs while you are inserting data, you probably need more room in the IQ main store. If the problem occurs during queries with large sort-merge joins, you probably need more room in the IQ temporary store.

    Check the SAP Sybase IQ message log for the following messages:
    • If a buffer or dbspace allocation request fails because there is no space in the dbspace, this error message is logged in the dbname.iqmsg message file:
      You have run out of space in %2 DBSpace. %1
      [EMSG_OUT_OF_DBSPACE: SQL Code -1009170L,
SQL State QSB66, Sybase Error Code 20223]
      where %2 is the name of the dbspace.
    • If the entire transaction is rolled back on an out-of-dbspace condition, you see:
      %1 -- Transaction rolled back"
      [IQ_TRANSACTION_ROLLBACK: SQL Code -1285L,
SQL State 40W09, Sybase Error Code 2973]
      where %1 is the error that caused the transaction to roll back, when encountered by the server during a critical operation.
    • If a buffer allocation request finds a dirty buffer, but the buffer manager cannot flush the buffer due to an out-of-space condition, you see this message, and the current statement rolls back:
      %2: All buffer cache pages are in use, ask your
DBA to increase the size of the buffer cache. %1
      [EMSG_BUFMAN_ALLSLOTSLOCKED: SQL Code -1009031L,
SQL State QSA31, Sybase Error Code 20052]
      where %2 is the particular buffer cache throwing the exception.

  • Try to connect to the database from a new connection. If this works, the database server is running, even though the query is waiting. Run sp_iqstatus to get more information.

  • If you cannot connect to the database, check if SAP Sybase IQ is in an unusable state by monitoring the CPU usage for that processor. If the CPU usage does not change over a small time interval, then SAP Sybase IQ is probably not operational. If the CPU usage does change, SAP Sybase IQ is operational.

  • Check the sp_iqstatus output for:
    Main IQ Blocks Used:,10188 of 12288,
82%, Max Block#: 134840
    Temporary IQ Blocks Used:,163 of 6144,
2%, Max Block#: 97
    If the percentage of blocks used is in the nineties, add more disk space with the CREATE DBSPACE command. In this example, 82% of the Main IQ Blocks and 2% of the Temporary IQ Blocks are used, indicating that more space will soon be needed in the IQ main store.

  • If out-of-space conditions occur, or sp_iqstatus shows a high percentage of main blocks in use on a multiplex server, run sp_iqversionuse to find out which versions are being used and the amount of space that can be recovered by releasing versions.

Parent topic: Resource Issues