I have a postgresql database set up with clients data split by schema.
Within sql I would like to identify for the table products which columns containing the string "id" exist
I'm trying to use the pg_... tables to identify these columns, but the below query appears to be bringing back results from across schemas despite the restriction on table_schema
SELECT *
FROM pg_class c
INNER JOIN pg_attribute a ON a.attrelid = c.oid
INNER JOIN pg_type t ON a.atttypid = t.oid
INNER JOIN information_schema.tables sch ON c.relname = sch.table_name
WHERE c.relname = 'products'
AND a.attnum > 0
AND a.attname LIKE '%id%'
AND table_schema = 'schema001'
I guess the schemas could be set up incorrectly or the where clause is incorrect - any help would be appreciated
Use pg_namespace and drop the information_schema:
SELECT nspname, relname, attname
FROM pg_class c
INNER JOIN pg_namespace n ON n.oid = c.relnamespace
INNER JOIN pg_attribute a ON a.attrelid = c.oid
INNER JOIN pg_type t ON a.atttypid = t.oid
WHERE c.relname = 'products'
AND a.attnum > 0
AND a.attname LIKE '%id%'
AND n.nspname = 'schema001';
Related
I'm trying to get indexes, primary keys, and all constraints for a schema in PostgreSQL using standard sql. Most of the posts I'm finding for how to do this use SQL syntax that is specific to PostgreSQL (I'd like to avoid this). This references include the following:
How do I get the primary key(s) of a table from Postgres via plpgsql?
https://wiki.postgresql.org/wiki/Retrieve_primary_key_columns
https://dba.stackexchange.com/questions/214863/how-to-list-all-constraints-of-a-table-in-postgresql
The following is what I am currently using. Do the queries shown below correctly query for the indexes, primary keys, and constraints for a given schema?
-- indexes
select
ns.nspname as schema,
t.relname as table_name,
i.relname as index_name,
a.attname as column_name,
ixs.indexdef as index_definition
from
pg_index ix
join pg_class i on ix.indexrelid = i.oid
join pg_class t on ix.indrelid = t.oid and t.relkind = 'r'
join pg_namespace ns on t.relnamespace = ns.oid
join pg_indexes ixs on 1=1
and ns.nspname = ixs.schemaname
and t.relname = ixs.tablename
and i.relname = ixs.indexname
join pg_attribute a on 1=1
and a.attrelid = t.oid
and a.attnum = any(ix.indkey)
where 1=1
and ns.nspname = 'webapi'
order by
1,2,3,4
;
-- primary keys
select
ns.nspname as schema,
t.relname as table_name,
i.relname as index_name,
a.attname as column_name,
ixs.indexdef as index_definition
from
pg_index ix
join pg_class i on ix.indexrelid = i.oid
join pg_class t on ix.indrelid = t.oid and t.relkind = 'r'
join pg_namespace ns on t.relnamespace = ns.oid
join pg_indexes ixs on 1=1
and ns.nspname = ixs.schemaname
and t.relname = ixs.tablename
and i.relname = ixs.indexname
join pg_attribute a on 1=1
and a.attrelid = t.oid
and a.attnum = any(ix.indkey)
where 1=1
and ix.indisprimary = true
and ns.nspname = 'webapi'
order by
1,2,3,4
;
-- constraints
select
ns.nspname as schema,
t.relname as table_name,
con.conname as constraint_name,
a.attname as column_name,
con.contype as constraint_type,
con.*
from
pg_constraint con
join pg_class t on con.conrelid = t.oid
join pg_namespace ns on t.relnamespace = ns.oid
join pg_attribute a on 1=1
and a.attrelid = t.oid
and a.attnum = any(con.conkey)
where 1=1
and ns.nspname = 'webapi'
order by
1,2,3,4
;
I have created a Materialized View in a Postgres Database. When I am creating my microstrategy cube connection to this Postgres Database, I am unable to see this Materialized View.
Can anyone help me to understand why I am unable to see this?
Thanks
You need to edit the read settings for your Warehouse Catalog.
Location: Schema->Warehouse Catalog Options->Catalog->Read Settings
Query for tables:
SELECT n.nspname as NAME_SPACE,
c.relname as TAB_NAME
FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind in ('v', 'm', 'r', 'p', '')
AND n.nspname <> 'pg_catalog'
AND n.nspname <> 'information_schema'
AND n.nspname !~ '^pg_toast'
ORDER BY 1,2
Column Query:
hanged to LEFT JOIN in on table INFORMATION_SCHEMA.COLUMNS (no issues for me so far)
SELECT DISTINCT
nspname AS NAME_SPACE,
relname AS TAB_NAME,
attname AS COL_NAME,
typname AS DATA_TYPE,
COALESCE(B.CHARACTER_MAXIMUM_LENGTH, attlen) AS DATA_LEN,
NUMERIC_PRECISION AS DATA_PREC,
NUMERIC_SCALE AS DATA_SCALE
FROM
pg_attribute A
JOIN
pg_class C
ON
A.attrelid = C.oid
JOIN
pg_namespace N
ON
C.relnamespace = N.oid
JOIN
pg_type T
ON
A.atttypid = T.oid
LEFT OUTER JOIN
INFORMATION_SCHEMA.COLUMNS B
ON
A.attname = B.COLUMN_NAME
AND C.relname = B.TABLE_NAME
AND N.nspname = B.TABLE_SCHEMA
WHERE
relname IN (#TABLE_LIST#)
AND attnum > 0
ORDER BY
1,
2,
3
Especially the columns query could be improved but until now I haven't looked back at this as it works fine.
Reason for all of this can be found in the following discussion: Materialized views don't show up in information_schema.
Found a workaround for this...
You can create the view as a standard view, connect this to Microstrategy, and then delete the view and created as a Materialized View. This will then pick up the newly created Materialized view as long as you keep the same name.
I have a partitioned table out of main table using range.
CREATE TABLE public.partition1 PARTITION OF public.maintable
FOR VALUES FROM ('2017-01-01 00:00:00') TO ('2050-01-01 00:00:00')
How can i get the Values range information using a query to postgres.
I have used a query that at least gives me information for the main and partitioned tables, but i cannot seem to find a way to access the value range
FROM ('2017-01-01 00:00:00') TO ('2050-01-01 00:00:00')
assigned to table partition1
Query used to get partition table information
WITH RECURSIVE partition_info
(relid,
relname,
relsize,
relispartition,
relkind) AS
(
(SELECT oid AS relid,
relname,
pg_relation_size(oid) AS relsize,
relispartition,
relkind
FROM pg_catalog.pg_class
WHERE relname = 'completedorders' AND
relkind = 'p')
UNION ALL
(SELECT
c.oid AS relid,
c.relname AS relname,
pg_relation_size(c.oid) AS relsize,
c.relispartition AS relispartition,
c.relkind AS relkind
FROM partition_info AS p,
pg_catalog.pg_inherits AS i,
pg_catalog.pg_class AS c
WHERE p.relid = i.inhparent AND
c.oid = i.inhrelid AND
c.relispartition = true)
)
SELECT * FROM partition_info;
The following query provides the information about partitions as well. From there on its just string manipulation in order to get further information.
Note: you will have to change the name of the table in the query.
with recursive inh as (
select i.inhrelid, null::text as parent
from pg_catalog.pg_inherits i
join pg_catalog.pg_class cl on i.inhparent = cl.oid
join pg_catalog.pg_namespace nsp on cl.relnamespace = nsp.oid
where nsp.nspname = 'public' ---<< change table schema here
and cl.relname = 'tablename' ---<< change table name here
union all
select i.inhrelid, (i.inhparent::regclass)::text
from inh
join pg_catalog.pg_inherits i on (inh.inhrelid = i.inhparent)
)
select c.relname as partition_name,
n.nspname as partition_schema,
pg_get_expr(c.relpartbound, c.oid, true) as partition_expression,
pg_get_expr(p.partexprs, c.oid, true) as sub_partition,
parent,
case p.partstrat
when 'l' then 'LIST'
when 'r' then 'RANGE'
end as sub_partition_strategy
from inh
join pg_catalog.pg_class c on inh.inhrelid = c.oid
join pg_catalog.pg_namespace n on c.relnamespace = n.oid
left join pg_partitioned_table p on p.partrelid = c.oid
order by n.nspname, c.relname
I thought it is straightforward but I couldn't find a way to list all tables and their creators (or owners) in Redshift. Any help/insight is welcome.
It was pg_tables table and here is the SQL:
select tablename, tableowner From pg_tables
You can list Redshift tables, views and their owners by running this script:
SELECT n.nspname AS schema_name
, pg_get_userbyid(c.relowner) AS table_owner
, c.relname AS table_name
, CASE WHEN c.relkind = 'v' THEN 'view' ELSE 'table' END
AS table_type
, d.description AS table_description
FROM pg_class As c
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
LEFT JOIN pg_tablespace t ON t.oid = c.reltablespace
LEFT JOIN pg_description As d
ON (d.objoid = c.oid AND d.objsubid = 0)
WHERE c.relkind IN('r', 'v')
ORDER BY n.nspname, c.relname ;
I need to query Redshift metadata to get a list of table columns that includes information whether the column is part of primary key or not.
There is a post already List columns with indexes in PostgreSQL that has an answer for PostgreSQL, however unfortunately, it fails on Redshift with "ERROR: 42809: op ANY/ALL (array) requires array on right side"
I figured out how to do it with the help of this https://bitbucket.org/zzzeek/sqlalchemy/pull-request/6/sqlalchemy-to-support-postgresql-80/diff
SELECT attname column_name, attnotnull,
format_type(atttypid, atttypmod) as column_type, atttypmod,
i.indisprimary as primary_key,
col_description(attrelid, attnum) as description
FROM pg_attribute c
LEFT OUTER JOIN pg_index i
ON c.attrelid = i.indrelid AND i.indisprimary AND
c.attnum = ANY(string_to_array(textin(int2vectorout(i.indkey)), ' '))
where c.attnum > 0 AND NOT c.attisdropped AND c.attrelid = :tableOid
order by attnum
The following worked for me:
SELECT n.nspname as schema_name,
t.relname as table_name,
i.relname as index_name,
c.contype as index_type,
a.attname as column_name,
a.attnum AS column_position
FROM pg_class t
INNER JOIN pg_index AS ix ON t.oid = ix.indrelid
INNER JOIN pg_constraint AS c ON ix.indrelid = c.conrelid
INNER JOIN pg_class AS i ON i.oid = ix.indexrelid
INNER JOIN pg_attribute AS a ON a.attrelid = t.oid
AND a.attnum= ANY(string_to_array(textin(int2vectorout(ix.indkey)),' ')::int[])
INNER JOIN pg_namespace AS n ON n.oid = t.relnamespace;
You can leverage the table DDL view AWS published a few months ago (https://github.com/awslabs/amazon-redshift-utils/blob/master/src/AdminViews/v_generate_tbl_ddl.sql) by picking out the constraint component and parsing out the key columns:
select schemaname,tablename, substring(ddl,charindex('(',ddl)+1, charindex(')',ddl)-1-charindex('(',ddl))
from
(
SELECT
n.nspname AS schemaname
,c.relname AS tablename
,200000000 + CAST(con.oid AS INT) AS seq
,'\t,' + pg_get_constraintdef(con.oid) AS ddl
FROM
pg_constraint AS con
INNER JOIN pg_class AS c
ON c.relnamespace = con.connamespace
AND c.relfilenode = con.conrelid
INNER JOIN pg_namespace AS n
ON n.oid = c.relnamespace
WHERE c.relkind = 'r'
ORDER BY seq
)
Note that this query also gives you foreign key columns. It's easy enough to filter those out by appending the query with
where ddl like '%PRIMARY KEY%'
Use below query:
select * from pg_table_def where tablename = 'mytablename'
This will give you all columns for table along with their data type , encoding and if it has sort key or dist key.