Ping. On Thursday, July 9, 2015 at 3:54:02 PM UTC-7, Wes Clark wrote: > > 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]> 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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