How to get index columns/dir/ord informations?

Hi!

I want to migrate some database to PG.
I want to make intelligens migrator, that makes the list of the SQL-s what
need to do to get same table structure in PG as in the Source DB.

All things I can get from the views about tables, except the indices.

These indices are not containing the constraints - these elements I can
analyze.

I found and SQL that get the index columns:

select
t.relname as table_name,
i.relname as index_name,
a.attname as column_name
from
pg_class t,
pg_class i,
pg_index ix,
pg_attribute a
where
t.oid = ix.indrelid
and i.oid = ix.indexrelid
and a.attrelid = t.oid
and a.attnum = ANY(ix.indkey)
and t.relkind = 'r'
and t.relname = 'a'
and ix.indisunique = 'f'
and ix.indisprimary = 'f'
order by
t.relname,
i.relname;

This can list the columns. But - what a pity - this don't containing that:
- Is this index unique?
- What the direction of the sort by columns
- What is the ordinal number of the column

So everything what I need to analyze that the needed index is exists or
not.

Please help me: how can I get these informations?
I don't want to drop the tables everytime if possible.

Thanks:
dd

Hi,

Query to list the tables and its concerned indexes.

SELECT indexrelid::regclass as index , relid::regclass as
table FROM pg_stat_user_indexes JOIN pg_index USING
(indexrelid) WHERE idx_scan < 100 AND indisunique IS FALSE;

Query will list the contraints.

SELECT relname FROM pg_class WHERE oid IN ( SELECT indexrelid FROM
pg_index, pg_class WHERE pg_class.oid=pg_index.indrelid AND (
indisunique = 't' OR indisprimary = 't' ) );

To get the column order number, use this query.

SELECT a.attname,a.attnum FROM pg_class c, pg_attribute a, pg_type t
WHERE c.relname = 'vacc' AND a.attnum > 0 AND a.attrelid = c.oid AND
a.atttypid = t.oid;

Note: This query for a particular Table 'VACC'

Best Regards,
Raghavendra
EnterpriseDB Corporation

On Fri, Apr 1, 2011 at 8:54 PM, Durumdara <durumdara@gmail.com
<mailto:durumdara@gmail.com>> wrote:

Hi!

I want to migrate some database to PG.
I want to make intelligens migrator, that makes the list of the
SQL-s what need to do to get same table structure in PG as in the
Source DB.

All things I can get from the views about tables, except the indices.

These indices are not containing the constraints - these elements
I can analyze.

I found and SQL that get the index columns:

select
t.relname as table_name,
i.relname as index_name,
a.attname as column_name
from
pg_class t,
pg_class i,
pg_index ix,
pg_attribute a
where
t.oid = ix.indrelid
and i.oid = ix.indexrelid
and a.attrelid = t.oid
and a.attnum = ANY(ix.indkey)
and t.relkind = 'r'
and t.relname = 'a'
and ix.indisunique = 'f'
and ix.indisprimary = 'f'
order by
t.relname,
i.relname;

This can list the columns. But - what a pity - this don't
containing that:
- Is this index unique?
- What the direction of the sort by columns
- What is the ordinal number of the column

So everything what I need to analyze that the needed index is
exists or not.

Please help me: how can I get these informations?
I don't want to drop the tables everytime if possible.

Thanks:
dd

Thanks:
dd

2011.04.01. 18:01 keltezéssel, Raghavendra írta:

Hi,

Query to list the tables and its concerned indexes.

SELECT indexrelid::regclass as index , relid::regclass as
table FROM pg_stat_user_indexes JOIN pg_index USING
(indexrelid) WHERE idx_scan < 100 AND indisunique IS FALSE;

Query will list the contraints.

SELECT relname FROM pg_class WHERE oid IN ( SELECT indexrelid FROM
pg_index, pg_class WHERE pg_class.oid=pg_index.indrelid AND ( indisunique =
't' OR indisprimary = 't' ) );

To get the column order number, use this query.

SELECT a.attname,a.attnum FROM pg_class c, pg_attribute a, pg_type t
WHERE c.relname = 'vacc' AND a.attnum > 0 AND a.attrelid = c.oid AND
a.atttypid = t.oid;

Note: This query for a particular Table 'VACC'

Best Regards,
Raghavendra
EnterpriseDB Corporation

On Fri, Apr 1, 2011 at 8:54 PM, Durumdara <durumdara@gmail.com> wrote:

Hi!

I want to migrate some database to PG.
I want to make intelligens migrator, that makes the list of the SQL-s what
need to do to get same table structure in PG as in the Source DB.

All things I can get from the views about tables, except the indices.

These indices are not containing the constraints - these elements I can
analyze.

I found and SQL that get the index columns:

select
t.relname as table_name,
i.relname as index_name,
a.attname as column_name
from
pg_class t,
pg_class i,
pg_index ix,
pg_attribute a
where
t.oid = ix.indrelid
and i.oid = ix.indexrelid
and a.attrelid = t.oid
and a.attnum = ANY(ix.indkey)
and t.relkind = 'r'
and t.relname = 'a'
and ix.indisunique = 'f'
and ix.indisprimary = 'f'
order by
t.relname,
i.relname;

This can list the columns. But - what a pity - this don't containing
that:
- Is this index unique?
- What the direction of the sort by columns
- What is the ordinal number of the column

So everything what I need to analyze that the needed index is exists or
not.

Please help me: how can I get these informations?
I don't want to drop the tables everytime if possible.

Thanks:
dd