BATCHEDREAD_TABLE configuration parameter

Use the BATCHEDREAD_TABLE configuration parameter to enable or disable light scans on compressed tables, tables with rows that are larger than a page, and tables with VARCHAR, LVARCHAR, and NVARCHAR data.

onconfig.std value
BATCHEDREAD_TABLE 1
values
0 = Disable light scans on variable record-length tables

1 = Enable light scans on variable record-length tables.

Compressed tables, and tables with rows longer than a page, are treated here as of variable record-length.
takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.

Usage

Except for compressed tables, tables with rows that are larger than a page, and tables of varying record length (such as VARCHAR, LVARCHAR, and NVARCHAR columns), the setting of BATCHEDREAD_TABLE has no effect on whether the query optimizer chooses a query execution path that includes a light scan.

The database server does not perform light scans on indexes, on system tables, nor on user tables whose rows include large objects with any of these storage attributes:
  • blobspaces
  • smartblob spaces
  • partition blob.

You can use the IFX_BATCHEDREAD_TABLE environment option of the SET ENVIRONMENT statement to override the value of the BATCHEDREAD_TABLE configuration parameter for the current session.


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