I just sent you an email with a link. Please confirm you got it. On Wednesday, July 8, 2015 at 10:44:10 PM UTC-7, Thomas Mueller wrote: > > Hi, > > Yes, that makes sense. I can reproduce the problem with a simple test case > (that creates many tables and indexes). I have an idea how this could be > solved by changing the database metadata code (MetaTable.java), but it is a > bit complicated. > > Just to confirm that this is not a MVStore or MVCC problem, but a general > problem reading database metadata: Can you reproduce the problem when you > append ";mv_store=false;mvcc=false" to the database URL, with a recent > version of H2 (but exactly the same version of com.guidewire.pl.system. > database)? > > Regards, > Thomas > > > > On Wednesday, July 8, 2015, Wes Clark <[email protected] <javascript:>> > wrote: > >> select count(*) from INFORMATION_SCHEMA.TABLES; >> COUNT(*) >> <http://10.58.2.44:8082/query.do?jsessionid=a463531bf3c62477a31f00116b7beda7#> >> 1713(1 row, 34 ms) >> >> select count(*) from INFORMATION_SCHEMA.INDEXES; >> COUNT(*) >> <http://10.58.2.44:8082/query.do?jsessionid=a463531bf3c62477a31f00116b7beda7#> >> 7557 >> This is "sample" database. We have four other databases which might be >> twice or three times as big, but same order of magniture. >> >> On Wednesday, July 8, 2015 at 9:35:49 AM UTC-7, Thomas Mueller wrote: >>> >>> Hi, >>> >>> You first indicate that the query can be sped by taking into account the >>>> schema name. >>>> >>> >>> I'm sorry! Yes, first I thought changing the query would help, but then >>> I found out there is no easy way to do that in this case. Even adding the >>> schema name as a condition will not help. That is, if you need all the info >>> that the query returns. The problem is the join (which is needed for the >>> "is nullable" column). This join will not use an efficient index. (Actually >>> there is an index, the MetaIndex, on the column "table_name", and this >>> index is used, but the index is inefficient if there are many tables). >>> >>> Later you indicate I should change the metadata, for example to use >>>> materialized metadata tables. >>>> >>> >>> That change would ideally be done in H2. >>> >>> >>>> What is the simplest way to make this query efficient? Can it be sped >>>> up by simply changing the query? >>>> >>> >>> That's a good question. >>> >>> How does your schema look like? How many tables and how many indexes and >>> schemas do you have? >>> >>> Regards, >>> Thomas >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "H2 Database" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/h2-database. >> For more options, visit https://groups.google.com/d/optout. >> >
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