DB2 V10-New Access Method~Hashing (2 of 2)

I discussed about hashing in my earlier post.Hash organization requires additional storage.

The real time statistics REORGHASHACCES is very low then we need to remove Hash organization from the table.

ALTER TABLE can be used to change the space for Hash.

Changing Hash space need

  • When the TOTALENTRIES in SYSINDEXSPACESTATS are greater than 10% of TOTALROWS in SYSTABLESPACESTATS.

  • When the real-time statistic DATASIZE in SYSTABLESPACESTATS is greater than HASHSPACE in SYSTABLESPACE; maintain HASHSPACE size at least 20% bigger than DATASIZE.

MAXROWS parameter should not be used with Hash.

In my next post I will write, when Index is required and not.

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