Can a PL/pgSQL function contain a dynamic subquery?

Posted by morpheous on Stack Overflow See other posts from Stack Overflow or by morpheous
Published on 2010-05-17T07:38:15Z Indexed on 2010/05/17 7:40 UTC
Read the original article Hit count: 269

Filed under:

postgresql

|

plpgsql

I am writing a PL/pgSQL function. The function has input parameters which specify (indirectly), which tables to read filtering information from.

The function embeds business logic which allows it to select data from different tables based on the input arguments. The function dynamically builds a subquery which returns filtering data which is then used to run the main query.

My questions are:

Is it 'legal' to use a dynamic subquery in a PL/pgSQL function. I cant see why not - but this question is related to the next one.
AFAIK, PL/pgSQL are cached or precompiled by the query engine. How does having a function that generates dynamic subqueries impact the work of the query engine?

© Stack Overflow or respective owner

Related posts about postgresql

Postgresql fails to start on Ubuntu 10.04.4 LTS

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I installed postgresql 9.2 from add-apt-repository ppa:pitti/postgresql using apt-get install postgresql-9.2 At the end of the install and every time I try to launch postgresql by using the following command /etc/init.d/postgresql start or service postgresql start I get this error: Error:… >>> More
can't install psycopg2 in my env on mac os x lion

as seen on Server Fault - Search for 'Server Fault'
I tried install psycopg2 via pip in my virtual env, but got this error: ld: library not found for -lpq (full log here: http://pastebin.com/XdmGyJ4u ) I tried install postgres 9.1 from .dmg and via port, (gksks)iMac-Alexander:~ lorddaedra$ locate libpq /Developer/SDKs/MacOSX10.7.sdk/usr/include/libpq /Developer/SDKs/MacOSX10… >>> More
Postgresql has broken apt-get on Ubuntu

as seen on Super User - Search for 'Super User'
On ubuntu 12.04, whenever I try to install a package using apt-get I'm greeted by: The following packages have unmet dependencies: postgresql-9.1 : Depends: postgresql-client-9.1 but it is not going to be instal led E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a so lution)… >>> More
Installing PostgreSQL on FreeBSD (with ports)

as seen on Server Fault - Search for 'Server Fault'
Hey everyone, I am trying to install (using ports) PostgreSQL on a virtual server, running FreeBSD. My one question is this: Which of the following should I install? postgresql-contrib postgresql-docs postgresql-jdbc postgresql-libpgeasy postgresql-libpq++ postgresql-libpqxx postgresql-odbc … >>> More
Strange permission errors in new PostgreSQL installation

as seen on Server Fault - Search for 'Server Fault'
A freshly installed PostgreSQL (with configuration overwritten) won't start: $ sudo service postgresql start * Starting PostgreSQL 9.1 database server * Error: could not read /etc/postgresql/9.1/main/postgresql.conf: Permission denied Looks like it should be able to read it though: $ ls -l postgresql… >>> More

Related posts about plpgsql

plpgsql function to generate random readable strings

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi I have written the following function but it's isn't returning anything when I run it. Can somebody help identify the issue? CREATE OR REPLACE FUNCTION GenerateReadableRandomString ( len INT ) RETURNS varchar AS $$ DECLARE validchars VARCHAR; randomstr VARCHAR; randint INT; … >>> More
PLPGSQL array assignment not working, "array subscript in assignment must not be null"

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello there, When assigning mobilenumbers to a varchar[] in a loop through results it gives me the following error: "array subscript in assignment must not be null" Also, i think the query that joins member uuids, and group member uuids, into one, grouped on the user_id, i think it can be done… >>> More
PLPGSQL : Return a record from function executed by INSERT/UPDATE rule

as seen on Stack Overflow - Search for 'Stack Overflow'
Do the following scheme for my database: create sequence data_sequence; create table data_table { id integer primary key; field varchar(100); }; create view data_view as select id, field from data_table; create function data_insert(_new data_view) returns data_view as $$declare _id… >>> More
Stored insert procedure in plpgsql

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to do something like this in PostgreSQL. I tried this: CREATE or replace FUNCTION create_patient(_name text, _email text, _phone text, _password text, _field1 text, _field2 text, _field3 timestamp, _field4 text, OUT _pid integer, OUT _id integer) RETURNS record AS $$ DECLARE _id… >>> More
Développer des fonctions scalaires (UDF) avec PLpgSQL, par SQLpro

as seen on Developper.com - Search for 'Developper.com'
Bonjour, voici le premier d'une nouvelle série d'articles consacrés au développement des fonctions sous PLpgSQL Ce premier article est consacré aux fonctions scalaires appelées dans la norme SQL "UDF" pour User Defined Function Il sera suivi dans les mois prochains de deux autres… >>> More