Re: Check for existence of index

And another thing, can't I do this:

create table s.a (blah);
create table s.b (blah);

create index myindex on s.a(blah);
create index myindex on s.b(blah);

? When I drop them I have to specify the schema name, so presumably it
tracks them that way. Why can't I have the same index name be on
different tables?

David Rysdam wrote:

> I have a script that automatically creates my database objects. In
> order to automatically create indexes, it needs to first make sure
> they don't exist.
>
> For things like tables, this is easy:
>
> select * from information_schema.tables where table_schema =
> "<myschema>" and table_name = "<tablename>"
>
> But for indexes it is hard for some reason. There's a catalog table
> "pg_index", but it doesn't have index, schema or table names. I
> eventually found them in pg_class but the table and schema names
> aren't there.
>
> After some searching around, I came across this very strange (to me,
> anyway) "::regclass" thing that let me do this:
>
> select * from pg_catalog.pg_index where indexrelid =
> 'schema.index'::regclass
>
> I'm not really clear what's that doing, but in any case it still isn't
> what I want. That query returns information when the index exists but
> errors out when the index doesn't exist. Is there a way I can get a
> non-erroring query on either condition that will tell me if an index
> exists on a given table in a given schema?
>
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