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I'm trying to drop a few tables with the "DROP TABLE" command but for a unknown reason, the program just "sits" and doesn't delete the table that I want it to in the database.
I have 3 tables in the database:
Product, Bill and Bill_Products which is used for referencing products in bills.
I managed to delete/drop Product, but I can't do the same for bill and Bill_Products. I'm issuing the same "DROP TABLE Bill CASCADE;" command but the command line just stalls. I've also used the simple version without the CASCADE option.
Do you have any idea why this is happening?
Update:
I've been thinking that it is possible for the databases to keep some references from products to bills and maybe that's why it won't delete the Bill table.
So, for that matter i issued a simple SELECT * from Bill_Products and after a few (10-15) seconds (strangely, because I don't think it's normal for it to last such a long time when there's an empty table) it printed out the table and it's contents, which are none. (so apparently there are no references left from Products to Bill).
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PostgreSQL has a DROP TABLE statement that is used to remove an existing table or tables from the database. Syntax: DROP TABLE [IF EXISTS] table_name [CASCADE | RESTRICT]; Let's analyze the above syntax: We specify the table name after the DROP TABLE keyword to remove the table permanently from the database.
Restriction on Dropping Tables You cannot directly drop the storage table of a nested table. Instead, you must drop the nested table column using the ALTER TABLE ... DROP COLUMN clause. Specify CASCADE CONSTRAINTS to drop all referential integrity constraints that refer to primary and unique keys in the dropped table.
The CASCADE option allows you to remove the table and its dependent objects. The RESTRICT option rejects the removal if there is any object depends on the table. The RESTRICT option is the default if you don't explicitly specify it in the DROP TABLE statement.
DROP TABLE removes tables from the database. Only the table owner, the schema owner, and superuser can drop a table. To empty a table of rows without destroying the table, use DELETE or TRUNCATE . DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table.
What is the output of
SELECT * FROM pg_locks l JOIN pg_class t ON l.relation = t.oid AND t.relkind = 'r' WHERE t.relname = 'Bill'; It might be that there're other sessions using your table in parallel and you cannot obtain Access Exclusive lock to drop it.
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Just do
SELECT pid, relname FROM pg_locks l JOIN pg_class t ON l.relation = t.oid AND t.relkind = 'r' WHERE t.relname = 'Bill'; And then kill every pid by
kill 1234 Where 1234 is your actual pid from query results.
You can pipe it all together like this (so you don't have to copy-paste every pid manually):
psql -c "SELECT pid FROM pg_locks l JOIN pg_class t ON l.relation = t.oid AND t.relkind = 'r' WHERE t.relname = 'Bill';" | tail -n +3 | head -n -2 | xargs kill If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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