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Reducing memory usage of HANA DB caused by table preload

HANA database periodically keeps track of the column attributes loaded in to the memory during a normal operation. This information is stored as table preload information, which in turn is used to load the column attributes back after each restart of the index server. This results in improvement of query execution, but it also causes the memory usage to go up.

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Use the following procedure to reduce the memory usage:
  1. Deactivate the preload feature of the index server temporarily by setting the reload_tables parameter in the sql section to false
  2. Deactivate the collection of table preload information in the indexserver.ini file by adding the parameter tablepreload_write_interval in the persistence section and setting the value to 0
  3. Restart SAP HANA
  4. Execute frequently used queries to load corresponding column table attributes into memory.
  5. Manually store the above information to be used for the next restart by excuting the command hdbcons "tablepreload writeinfo"
  6. Re-activate the preload feature in the indexserver.ini file by setting the reload_tables parameter in the sql section to true. The stored table preload information will be used at the next restart.

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