SQL query caching is in there... -----Original Message----- From: Max Andersen Sent: Sunday, November 06, 2005 11:53 AM To: Steve Ebersole; Hibernate development Subject: Re: [Hibernate] query plans
Nice stuff - give a ping when sql query caching is in there somewhere ;) btw. if you know by heart what you replace sessionFactoryImpl.getQuery(query, false, Collections.EMPTY_MAP); then let me know ;) (or do i need a session now to create a query and get the generated sql etc. ?) /max > As an fyi... > > I just checked in a bunch of changes related to how queries > "translations" are cached. I added a new concept of "query plans" and a > QueryPlanCache to encapsulate the role that used to be filled by the > building and caching of the QueryTranslator arrays within > SessionFactory. This has a number of significant ramifications: > > 1) HQL queries and collection-filters are now translated as soon as they > are encountered (i.e. as soon as createQuery()/createFilter() are > called). Two important things to note here: first, grammar problems > will now show up immediately as opposed to delayed until first > execution. Second, this allows much better "parameter type guessing" > within the Query impls when one of the untyped forms of setParameter() > is called. Minorly, (although not yet exposed) this also allows the > Query impls to no the "source query location" of all parameters > (important for the tools). > > 2) Native-SQL query "translations" are now cached. This caching, > however, happens only after first execution since not all pertinent > information is known at the time createSQLQuery() is called. Currently, > named native-SQL queries are not cached at SF startup, but I'll add that > support next week. The SQLQueryImpl also knows its "parameter metadata" > just like HQL/collection-filters, but there is not enough information to > properly do the "expected type" stuff done in HQL and > collection-filters. > > 3) Allowed me to remove the "evil" initParameterBookkeeping stuff that > used to be done on AbstractQueryImpl which should result in some minor > performance increases (this stuff used to parse the query string each > and every time a Query impl was obtained). > > 4) Especially for those of you interested in tools development, I > created a new class that is responsible for "reconginizing parameters" > within query strings in a unified manner. This class, for example, is > now used exclusively within the query plans to determine the proper > "parameter locations". Essentially, it is a very simple parser with a > small pre-defined number of recognized tokens. Have a look at > org.hibernate.engine.query.ParameterParser and especially the different > impls of org.hibernate.engine.query.ParameterParser$Recognizer. > > Anyway, all this is still not completely done to my satisfaction, but > it's a good start. > > Because these are some very broad changes, I will plan to go with a > 3.1rc3 including this stuff (maybe late next week). The current plan is > that 3.1 final will then be the release after that. > > P.S. part of these changes required a modification to the constructor > for AbstractQueryImpl to add a new parameter. There were two > constructors on SQLQueryImpl for which I could not find any usages > within the Hibernate core code-base. If these effect someone (tools?, > annotations?, ejb3?) let me know. Otherwise I actually plan to go back > and remove those constructors. > > > ------------------------------------------------------- > SF.Net email is sponsored by: > Tame your development challenges with Apache's Geronimo App Server. > Download > it for free - -and be entered to win a 42" plasma tv or your very own > Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php > _______________________________________________ > hibernate-devel mailing list > hibernate-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/hibernate-devel -- -- Max Rydahl Andersen callto://max.rydahl.andersen Hibernate [EMAIL PROTECTED] http://hibernate.org JBoss Inc [EMAIL PROTECTED] ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php _______________________________________________ hibernate-devel mailing list hibernate-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hibernate-devel
