Subject Database settings for large tables
Author Toby Moxham

We have a number of clients who have quite large databases with pretty much all the data in two tables, we perform a searching on these two tables with a join.

The database sizes go up to around 11GB, one issue we are experiencing is that the query time can vary considerably, some times we will get results back in a couple of seconds and then moments later a similar query can take minutes. Which I assume is something to do with how its being cached.

We would like to know the optimum settings for cache/buffers etc for a large database, we have changed the pagesize to 16k and experimented with the DefaultDbCachePages, when setting DefaultDbCachePages it seems to improve it and we can see firebird using a lot more memory, however it seems to release the memory very quickly and then queries can become slow again, are there any other settings that we should be looking at.

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