#Postgresql delete table if exists code

But without more details I can't suggest any possible way to do it. DROP TABLE IF EXISTS temporarytablename Example: Explicitly Removing a TEMP Table in Postgres Let’s first create a temporary table by executing the following command: CREATE TEMP TABLE cptable ( id INT, name VARCHAR ) The above snippet shows that a temporary table has been created using a TEMP keyword. If a table that you need to delete has foreign key references, then specify the option CASCADE CONSTRAINTS. Then maybe you don't need any intermediate storage at all. I would probably try to re-write the function to be able to work on multiple rows and then join that in the outer query rather calling it in the SELECT list as you seem to be doing. Hundreds or a few thousands should be OK though.Īlternatively you create a type that represents the function's result and aggregate the result into an array of the record type (rather than having four arrays). Of course, this is only feasible if the function doesn't return millions of rows. Into c1_result, c2_result, c3_result, c4_result Something like: select array_agg(c1), array_agg(c2), array_agg(c2), array_agg(c3) One way to work around the temp table could also be to store the result into arrays.

#Postgresql delete table if exists code

But without seeing more of the code (the 'calls other function.' part), I can't offer any alternatives. So that no intermediate storage is needed at all. I would be inclined to do everything in a single statement that joins to the result of the function call, rather than storing the result somewhere. This is really hard to answer, because you don't show the big picture. What is an alternative to dropping/creating temp tables, if you need a 'table variable' in a function? select remove_vertices(geom) from some_table), the dropping and creation of the temp table can occur as many times as there are rows in a table. Only one index name can be specified, and the CASCADE. There are several caveats to be aware of when using this option. With this option, the command instead waits until conflicting transactions have completed. Since this function is supposed to be called per row of a table (i.e. A normal DROP INDEX acquires an ACCESS EXCLUSIVE lock on the table, blocking other accesses until the index drop can be completed. Then - do something with invalid_pnts table and the input 'par_geom' Select count(*) into cnt from invalid_pnts where X corresponds to number of faulty vertices in a postgis geometry selfintersects(par_geom) returns X rows with 4 columns/attributes, I have tried to increase the max_locks_per_transaction, but it still occurs.Īs far as i understand from the answer in this post ('PostgreSQL complaining about shared memory, but shared memory seems to be OK') creating and dropping temp tables creates locks which can result in the earlier-mentioned warning.įor example: create or replace function remove_vertices(par_geom geometry) I have been creating some functions lately that run into the 'out of shared memory' warning in postgres.