2010/3/18 Heikki Linnakangas <heikki.linnakan...@enterprisedb.com>: > Pavel Stehule wrote: >> attached patch add possibility to share ispell dictionary between >> processes. The reason for this is the slowness of first tsearch query >> and size of allocated memory per process. When I tested loading of >> ispell dictionary (for Czech language) I got about 500 ms and 48MB. >> With simple allocator it uses only 25 MB. If we remove some check and >> tolower string transformation from loading stage it needs only 200 ms. >> But with broken dict or affix file it can put wrong results. This >> patch significantly reduce load on servers that use ispell >> dictionaries. >> >> I know so Tom worries about using of share memory. I think so it >> unnecessarily. After loading data from dictionary are only read, never >> modified. Second idea - this dictionary template can be distributed as >> separate project (it needs a few changes in core - and simple >> allocator). > > Fixed-size shared memory blocks are always problematic. Would it be > possible to do the preloading with shared_preload_libraries somehow?
Maybe. But there are some disadvantages: a) you have to copy dictionary info to config, b) on some systems can be a problem lot of memory per process (probably not on linux). Still you have to do some bridge between tsearch cache and preloaded data. Pavel > > -- > Heikki Linnakangas > EnterpriseDB http://www.enterprisedb.com > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
