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PostgreSQL: How to list all stored functions that access specific table

Introduction: PostgreSQL database with several hundred of stored functions, including obsolete, not used etc. Problem I need to find out all the stored functions that have any relationship to the ...
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9k views

Error “column does not exist” in a SELECT with JOIN and GROUP BY query

I'm using PostgreSQL 9.1 with a Ruby on Rails application. I'm trying to list the last version of each "charge" (in my history table : hist_version_charges) belonging to the same project id (...
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3answers
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how to chain postgres RULEs?

I have implemented data denormalization strategy using postgresql RULEs. I picked rules instead of triggers for performance reasons. Schema is structured like this: Application has many clients ...
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2answers
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Why might my Postgres table be growing?

I've got a table that grows under Postgres 9.1. It's a high-throughput table with lots of inserts and deletes, but it should generally remain between 1-2k in terms of number or records. Auto-vacuum is ...
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Unable to disable SQL statement logging in PostgreSQL 9.1

I am running PostgreSQL 9.1 on Windows Server 2008 R2. I enabled SQL statement logging to the stderr log by modifying my postgresql.conf file, but now I can't seem to disable the logging without ...
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Recover PostgreSQL database from WAL errors on startup?

I'm trying to set up an OpenStreetMap server on an Ubuntu 12.04 machine using the Ubuntu packages listed at switch2osm.org. I initially installed and set up everything using a Northeast US-only map ...
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2answers
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psql won't list databases

I have a situation that I'm scratching my head over, but I'm new to postgresql, so I may be overlooking something obvious. I set up a testbed server and set access in pg_hba.conf: local all ...
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1answer
3k views

Does my choice of pg_dump format impact restore speed?

According to the docs for my version of Postgres (8.4.2), pg_dump can "output in script or archive file formats." The script-formatted dump (4GB) takes 1.5 hours to restore, and I'm wondering if the ...
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2answers
331 views

What is the consensus on using NOT NULL constraints on all text-based fields in a table?

Some of the tables I have come across don't have any NOT NULL constraints, which has yielded to some gotchas when querying. I'm curious what the feelings are with using something like NOT NULL ...
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How hard would it be to have PostgreSQL run a test to adjust the cost parameters?

By using EXPLAIN one can see the cost of running a query. The cost is in artificial units, and they are based on pre-defined parameters. 1 is one disk fetch and a CPU cycle is 0.01 units, I believe. ...
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4answers
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Select rows for which at least one row per set meets a condition

I have following table: create table test ( company_id integer not null, client_id integer not null, client_status text, unique (company_id, client_id) ); insert into test values (1, 1, '...
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2answers
81 views

Select tables on column entry in schema (with many tables)

I have a schema in a PostgreSQL-DB that includes approx. 3000 tables with each having one row/ entry (size, id, geom). I'd like to select all tables which have a size value lower than 20. How can I ...
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2answers
217 views

Optimize query to find top N users who commented on a post

Problem Trying to find the most efficient query to retrieve the top N (5 in the examples) users who have commented on a post, where a user is considered 'top' if they have the most followers. The ...
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2answers
112 views

Optimize a query with small LIMIT, predicate on one column and order by another

I'm using Postgres 9.3.4 and I have 4 queries that have very similar inputs but have vastly different response times: Query #1 EXPLAIN ANALYZE SELECT posts.* FROM posts WHERE posts.source_id IN (...
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1answer
470 views

Uniqueness constraint with date range

Consider a prices table with these columns: id integer primary key product_id integer -- foreign key start_date date not null end_date date not null quantity integer price numeric ...
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163 views

is it possible to run postgres with no WAL files being produced?

I am looking at a way of running a 9.2 postgres database on redhat 6 without any WAL files being produced. We have a end of day batch process which generates a large number of WAL files (and has ...
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Local Backup from Amazon RDS PostgreSQL database

I have a PostgreSQL database on an Amazon RDS instance. I want to have a local dump of this instance. So far, I've tried with this: PGPASSWORD="Password" pg_dump -h mydb.xxxxxx.us-east-1.rds....
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How to get exception context for a manually raised exception in PL/pgSQL?

In Postgres, we get the "stack trace" of exceptions using this code: EXCEPTION WHEN others THEN GET STACKED DIAGNOSTICS v_error_stack = PG_EXCEPTION_CONTEXT; This works fine for "natural" ...
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Postgresql doesn't accept replication connection

Plain old streaming replication. PostgreSQL: 9.2.7 Windows 8.1 64 bit My primary and secondary clusters are on same windows machine. I have already done pg_start_backup() and everything, so both ...
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Temporary schema per connection?

I am trying to migrate my unit tests from H2 to Postgresql. Currently, H2 gives me an in-memory schema such that each connection maps to a unique schema, creates the tables, runs the test, and drops ...
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1answer
846 views

Has postgresql a fast add column optimization?

When adding not-null columns with a default value - does Postgresql optimizes this operation? In case the table has n rows, a not-optimized alter-table-add-column would yield n writes of the default ...
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What is the fastest way to fetch the last row from a table?

I have a PostgresSQL table, Prices, with the columns: price (Decimal) product_id (Int) Prices get updated regularly and I keep old prices in the table. For a given product, the last price in the ...
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1answer
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Postgres on Engineyard space at 100%, pg_xlog filled up with files

I have a database that is growing rapidly. VERY rapidly. My /db directory is at 100% now, and there are a bunch of new files in pg_xlog. My background is in Oracle and MySQL. I do not know what is ...
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How to do a minor upgrade postgresql 9.3.0 windows to 9.3.1?

What is the recommended way to perform an upgrade from PostgreSQL 9.3.0 to 9.3.1 (minor upgrade) using the Enterprise DB built windows installer? Should I uninstall first or just install over the ...
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Can column name be “Group” in Postgresql or in any databases

I was designing a project which specifies that in a table what column name should be and one of the column name in the specification is "group". I tried creating it but it always throw a syntax ...
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PostgreSQL CREATE TABLE creates with incorrect owner

I'm using PostgreSQL 9.2.4. When I create a table as a non-superuser in a database owned by that non-superuser, it is owned by the postgres user, so I can't put any data into it unless I explicitly ...
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Why does postgres use more space for a time with timezone than a timestamp with timezone?

The documentation on date/time data types state that timestamp with timezone takes 8 bytes, while time with timezone takes 12 bytes. They both have the same resolution (1 microsecond), and on the face ...
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1answer
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No way to set maximum retrieved rows in pgadmin query tool

I'm using version 1.16.1, and I can't find a "max(imum) rows" param to tweak. Any help would be appreciated.
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1answer
176 views

Why do psql queries take longer when inserting many rows. Why is it non linear

So if I insert a single row into a postgres database it takes 18 ms. If I do this in a loop like this: INSERT INTO contacts (numbers) SELECT distinct array[ (random() * 99999999)::integer, ...
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1answer
1k views

Most efficient to prevent duplicates

I'm building an application that will fetch messages with JSON every once in a while and store these in a postgres db. Now I want to prevent duplicates, so I calculate the sha-512 of the message and ...
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1answer
11k views

Declare variable of table type in PL/pgSQL

I am wondering if there is a way to declare a variable of type table in PL/pgSQL to hold query results? For instance how can I express something like: q1 = select * from foo; q2 = select * from bar; ...
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What is PostgreSQL database ownership

When creating a PostgreSQL database one can assign another role to be an owner of that database. What can the new owner do with this database? How is it compared to grants?
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Postgresql - Internal Array handling - array type or pointer type

I have a question, about the internal handling of array columns in Postgres. Does the engine handle it as a classical array with memory alloc or is it somehow a pointer list. It would be interesting ...
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1answer
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Will FK ON UPDATE CASCADE work?

Intuitively, adding the option ON UPDATE CASCADE to a foreign key constraint will have the effect of updating all referencing columns with the updated value of the key. Would that really work? ...
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2answers
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Reindexing a large database

I have a very large database (millions of rows) which has been indexed. I receive a diff of rows from another source that I need to update in my database. The problem I am facing is that is it ...
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2answers
584 views

Huge database logging of event type rows and ways to optimize it

We have a database that stores events. Events are generated at a 1000 per sec rate. We need to keep these events accessible for some years. Usual use of these events is selecting some of them from the ...
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2answers
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Understanding time format of the EXPLAIN command - Postgres

When I run the EXPLAIN ANALYZE command on a given query, I'm having a difficult time interpreting the outputted time value. For example (actual time=8163.890..8163.893). Do the internal decimals ...
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Postgres plpgsql - Using a variable inside of a dynamic create statement

Using Postgres pl/pgsql, I'm attempting to create a table using a dynamic EXECUTE command, such as: ... DECLARE tblVar varchar := "myTable"; BEGIN EXECUTE 'CREATE TABLE $1 ( foo ...
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1answer
183 views

What does “Heap Block” in “Bitmap Heap Scan” mean?

I have this query: EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM test WHERE timestamp_range @> '2015-01-22 23:00:00'::timestamp AND data_int_array @> '{49, 61}'::integer[]; Which outputs: ...
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1answer
151 views

How to avoid invoking functions twice when using GROUP BY and HAVING?

I have a PostgreSQL database (9.2) with a table of parent-child relations. I have a query that looks for nodes having multiple parents. The following query works and returns the correct results: ...
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1answer
438 views

Performance issues with inherited tables and indices

I have a PostgreSQL database with a master table and 2 child tables. My master table: CREATE TABLE test ( id serial PRIMARY KEY, date timestamp without time zone ); CREATE INDEX ON test(...
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1answer
175 views

Slow window function query with big table

I'm doing some performance testing on a new DB design on PostgreSQL 9.4rc1 and I'm seeing some pretty slow queries using window functions. Here is my table setup: CREATE TABLE player_stat ( ...
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1answer
258 views

Truncate parent table but not children

I have a table in PostgreSQL 9.4 that I partitioned so that all inserts to the parent actually go into one of the child partitions. The problem is that I already have hundreds of millions of rows of ...
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2answers
2k views

Add function parameter to SQL query WHERE clause

I have a web application in java and it uses a query. I don't want to write the query into Java, so I made a function: CREATE OR REPLACE FUNCTION testFunc(inputs text) RETURNS TABLE(...) AS $$ ...
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2answers
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Slow index scans in large table

Using PostgreSQL 9.2, I have troubles with slow queries on a relatively large table (200+ million rows). I'm not trying anything crazy, just adding historic values. Below is the query and the query ...
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1answer
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Why use RDS over EC2 for Postgres?

I have a database currently running on EC2. As I have to move it to a bigger machine the question of using RDS came up. Pricing: I can get an EC2 c3.large instance with two SSDs (16GB each), two ...
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How to optimise window queries in postgres

I have the following table with approximately 175k records: Column | Type | Modifiers ----------------+-----------------------------+-----------------------...
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707 views

Pull data from multiple tables in a view or function

There are 3 tables from which I need to pull data, and print it in a specific way. http://sqlfiddle.com/#!15/59481/8 Refer to this question to see how the query was produced. The version in the ...
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How to SUM previous sum, e.g N = (N-1) + (N-2) + … + 1?

I have a table name "TABLE_A (id integer, no integer)" . I want to sum "no" with group by "id" and current "sum of no" = previous "sum of no" Here is my code : 1/ Create table & insert data: ...
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2answers
242 views

Compound Index on 43 Million PostgreSQL table

This question is related to a prior one of I asked: Order of columns in a compound index in PostgreSQL (and query order) Rather than overload that question, I figure I can sharpen and limit my ...