Subject Re: [firebird-support] Server and DB page sizes and memory
Author Ann W. Harrison
Erik LaBianca wrote:
> I too have been having problems with insufficient performance due to
> lack of memory. I have a table of approximately 4.5 million records
> which I am working with. The .fdb file ends up using around 1GB of disk
> space, although adding a bunch of indexes push it up around 1.8GB.
> Among other things I need to be able to 'walk' the database in sorted
> order setting a 'sequence number'.

Have you looked at the sort memory parameters in the configuration
file? You can increase the size of the in-memory sort block and
avoid writing out intermediate files. The behavior you're seeing
(fast with smaller chunks, slow with large chunks) suggests that
your problem is with writing and reading sort files from the
temporary directors. You might also point the firebird temporary
directory to a RAM disk.

# In-memory sorting module
# The amount of memory allocated for each sort block.
# Type: integer
#SortMemBlockSize = 1048576

# The maximum amount of memory to be allocated by the in-memory
# sorting module.
# For Classic servers, this setting is defaulted to 8 MB.
# Although it can be increased, the value applies to each client
# connection/server instance and thus consumes a lot of memory.
# Type: integer
#SortMemUpperLimit = 67108864