Here’s the description from the PostgreSQL 8.1 docs: DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. We can put a list of tables after the DROP TABLE to remove multiple tables at once, each table separated by a comma. RESTRICT. However, due to viewing the foreign-key block of a table or any other table, CASCADE … CASCADE. The DROP table removes any indexes, rules, triggers, and obstacles that are present for the target table. Drop the big and little table if they exists. Is it expected that DROP table CASCADE drops this table and just the foreign key constraints but not the refering tables… 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.. CASCADE. RESTRICTrefuses to drop table if there is any object depends on it. DROP CASCADE. However, if there are external dependencies, such as views, this is not possible without DROP CASCADE. The second drop statement does not require the cascade keyword because there is not a dependent foreign key constraint. However, if you want to use selective delete with a where clause, TRUNCATE is not good enough.. USE WITH CARE - This will drop all rows of all tables which have a foreign key constraint on some_table and all tables … The first drop statement requires a cascade because there is a dependent little table that holds a foreign key constraint against the primary key column of the big table. Also, you can include all inheriting tables when dropping the parent table using the CASCADE key word: A parent table cannot be dropped while any of its children remain. To speed things up you can drop your constraints first, and/or TRUNCATE the table you want to drop. PostgreSQL uses RESTRICT by default. I have 3 tables in the database: Product, Bill and Bill_Products which is used for referencing products in bills. If you wish to remove a table and all of its descendants, one easy way is to drop the parent table with the CASCADE option. First, the CASCADE option is not … If you really want DELETE FROM some_table CASCADE; which means "remove all rows from table some_table", you can use TRUNCATE instead of DELETE and CASCADE is always supported. (Emphasis mine.) We can put a list of tables after the DROP TABLE to remove multiple tables at once, each table separated by a comma. When you execute the DROP INDEX statement, PostgreSQL acquires an exclusive lock on the table and block other accesses until the index removal completes.. To force the command waits until the conflicting transaction completes before removing the index, you can use the CONCURRENTLY option.. The DROP INDEX CONCURRENTLY has some limitations:. Even though the TRUNCATE TABLE statement removes all … If columns need to be added in the middle of a large table and order is important, the best way is to drop and recreate the table. Hi I encountered something that puzzled me a bit. CONCURRENTLY. Automatically drop objects that depend on the table (such as views). Automatically drop objects that depend on the function (such as operators or triggers), and in turn all objects that depend on those objects (see Section 5.13). The CASCADE option should be used with further consideration or you may potentially delete data from tables that you did not want.. By default, the TRUNCATE TABLE statement uses the RESTRICT option which prevents you from truncating the table that has foreign key constraint references.. PostgreSQL TRUNCATE TABLE and ON DELETE trigger. 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