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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL Informix® database servers.
Performance GuideThe Informix® Performance Guide describes how to configure and operate your HCL Informix® database server to improve overall system throughput and to improve the performance of SQL queries.
Improving individual query performanceYou can test, monitor, and improve queries.
Update statistics when they are not generated automaticallyThe UPDATE STATISTICS statement updates the statistics in the system catalog tables that the optimizer uses to determine the lowest-cost query plan.
Drop data distributions if necessary when upgradingWhen you upgrade to a new version of the database server, you might need to drop distributions to remove the old distribution structure in the sysdistrib system catalog table.
Drop distributions in LOW mode without gathering statisticsYou can remove distribution information from the sysdistrib table and update the systables.version column in the system catalog for those tables whose distributions were dropped, without gathering any LOW mode table and index statistics.

Drop distributions in LOW mode without gathering statistics

You can remove distribution information from the sysdistrib table and update the systables.version column in the system catalog for those tables whose distributions were dropped, without gathering any LOW mode table and index statistics.

You do this using the DROP DISTRIBUTIONS ONLY option in the UPDATE STATISTICS statement. Using the DROP DISTRIBUTIONS ONLY option can result in faster performance because the database server does not gather the table and index statistics that the LOW mode option generates when the ONLY keyword does not follow the DROP DISTRIBUTIONS keywords.

For detailed information about how to use the DROP DISTRIBUTIONS ONLY option, see the Informix® Guide to SQL: Syntax.

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