Hi, charles loboz wrote: > How can I change SQLite cache size for R session? > > SQLite cache size can be set by a pragma, for the > duration of the session - or by default. > .pragma cache_size > .pragma default_cache_size > > my questions are about RSQLite, version 0.4, running > on Windows: > - what is the cache size set to when SQLite is > invoked from R? > - if the page_size is set to 4096 what will be the > cache size in bytes when cache_size 1000 is specified? > (in other words: does R know about the page size > setting?)
No, R doesn't know about these settings, nor it needs to. According to the SQLite documentation "Pragmas to modify library operation" at http://www.sqlite.org/pragma.html, you can set the cache size (for the current session) with > library(RSQLite) Loading required package: DBI > con <- dbConnect(SQLite(), "/tmp/foo3.db") > dbGetQuery(con, "pragma cache_size") cache_size 1 2000 > dbGetQuery(con, "pragma cache_size=2500") NULL > dbGetQuery(con, "pragma cache_size") cache_size 1 2500 Hope this helps, -- David > > > > > P.S. Very impressed with SQLite and its (embedded) > integration with R - using it fully really simplifies > a lot of programming as well as moving computations > between computers. It is also, for my current needs, > much faster than postgress and much less cumbersome in > operation (permissions, administration, mobility). The > price to pay - need to be careful with crafting SQL - > no optimizer here. However, controlling cache size is > an important thing for any database and I would like > to know how to do it for R. Documentation does not > mention it and quick scan of the source code of > RSQLite did not show any obvious comments. > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
