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
>

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