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1answer
167 views

Does the length of a table name affect performance?

PostgreSQL table names are limited to 63 chars. Is there a performance gain to be had if I limit my table names to something like 5 chars or can I use the full 63 chars without consequence? I ...
2
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1answer
1k views

INSERT using results of CTE INSERT to provide unique id values

I am writing a job to transform data from an old design into a new design. In this process, I need to take the id from an insert into a separate table and use that in an insert to the target table, as ...
3
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1answer
8k views

How to convert a unix time to PostgreSQL' Timstamp without timezome?

I have a PostgreSQL database running on a server which has its time zone set to India's Time Zone (i.e. UTC +5:30) I have some data in a table which is created like this: CREATE TABLE "CLOUDDATA" ( ...
2
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1answer
792 views

Vacuum in postgresql and Purge in mysql

Do the vacuum operation in postgresql and purging operation in mysql perform the same tasks?
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1answer
1k views

How to access NEW or OLD field given only the field's name?

I'm writing a validation trigger. The trigger must validate that the sum of an array equals another field. Since I have many instances of this validation, I want to write a single procedure and create ...
7
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2answers
4k views

Get WAL files from AWS RDS PostgreSQL instance

We have a Postgres RDS instance on Amazon Web Services. We have automatic backups enabled, and we take snapshots on a daily basis. We would like to generate a local 'up-to-date' backup of the RDS ...
2
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1answer
887 views

Trouble with installing additional modules on Postgresql 9.1 on ALT-Linux

I'm trying to create extension under postgresql 9.1 (Linux): CREATE EXTENSION pg_trgm; but got error: ERROR: could not open extension control file "/usr/share/pgsql/extension/pg_trgm.control": No ...
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2answers
3k views

Replicating some tables from one postgres database to another

I've got the following situation: I have three machines running postgresql databases. One machine holds client account information (call this machine C), the other two machines hold client logging ...
1
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2answers
453 views

Basic trigger in PL/pgSQL, to flip a boolean field if another field has text

I want a BOOLEAN field to be set to TRUE when a sibling TEXT field is set to a non-empty string. Vice versa, the BOOLEAN is set to FALSE when TEXT field is set to empty string. The following function ...
4
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1answer
4k views

How to edit `postgresql.conf` with pgAdmin?

How does one edit the 'postgresql.conf' file with the pgAdmin app? With pgAdmin 1.18.1 on Postgres 9.3.x, when I choose File > Open postgresql.conf I get a file picker dialog. And, yes, I'm connected ...
1
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1answer
577 views

Self-join unique pairs

I have a table (players) containing a list of players, I would like to pair up these players in a unique way, so that every player's opponent is unique every round (ie. every time the SELECT query is ...
5
votes
2answers
6k views

PGAdmin3 connection with non standard SSH port and SSH tunnel

Hi I am trying to connect to Postgres from pgAdmin3 using SSH tunneling. However I am not using standard port 22. How can I do SSH tunneling using a non standard port?
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0answers
518 views

Performance measurement in PostgreSQL

When developing server-side stored procedures performance measurement is an important issue. EXPLAIN ANALYZE is very usefull, but when it comes to simple queries like SELECT name FROM clients WHERE ...
0
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2answers
146 views

compare dates in results

I'm looking to compare the dates in the result set Example: SELECT * FROM tbl WHERE foo=bar Output id, datetime, name 1, 2014-01-01 18:13:45, test 1 2, 2014-01-01 19:01:32, test 2 3, 2014-01-01 ...
4
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2answers
212 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 ...
1
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0answers
110 views

Trouble adding foreign key on lots of data in Postgres

Working with PostgreSQL 9.0.8 on linux. Can't add foreign key. I have two tables: Table1 and Table2. Table1 has 10 columns and 200 000 rows filled with some data, where first column is 'id' (primary ...
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0answers
282 views

Reset postgresql [closed]

I have trouble: I tried to restore PG backup from CentOS on my Ubuntu computer. But had a trouble: after placing backuped Centos /var/lib/pgsql/9.1/data/ to my /var/lib/postgresql/9.1/main at Ubuntu, ...
4
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1answer
106 views

restarting postgresql quickly

I'm reading over the postgresql admin cookbook. Some of the database server parameters require a restart and with a busy database, you may need to restart quickly. There are a number of things to do ...
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2answers
1k views

Is this temp table behaviour documented?

Query Language (SQL) and PL/pgSQL functions treat temp tables differently: begin; create table foo(id) as values (1); select * from foo; /* id ---- 1 */ savepoint s; create function f() returns ...
0
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2answers
81 views

PgPool fails to auth in master_slave mode

We have two PostgreSQL servers running in master-slave streaming replication mode, behind pgpool. When we activate master_slave mode in pgpool.conf, we get following error: do_md5 failed in slot 1 ...
5
votes
1answer
2k views

Get postgres snapshot from Amazon RDS

I can not find a simple way to get a copy of the nightly backup I take of my Amazon RDS postgres instance so I can restore it on my local machine to play with. Right now I'm doing a pg_dump when I ...
3
votes
1answer
612 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 ...
0
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1answer
203 views

Postgresql: How to add a role that inherits from another?

Pretty cut and dry, I am just a total noob. Is there a way to make a given role inherit from another?
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0answers
136 views

Postgresql 9.2 - Auto vacuum running continuously for 18+ hours

I currently have a table that is updated daily (easily 20%+ rows are updated, all floats/integers) and the vacuum is kicking off and running for more than 18 hours. There are 19 million rows total. ...
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1answer
2k views

Postgresql restore data from file [duplicate]

I have a tar archive with full backup of my CentOS filesystem with pg9.1 installed. How can I restore one database from it?
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3answers
157 views

Drop database owned by specific user in PostgreSQL

I have created database with bad symbols at the end of its name. Now I want to drop it but I don't know how to type its name in the console. Can I remove databases owned by this user? I tried to DROP ...
1
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0answers
92 views

Do supertables produce bottlenecks?

There are several alternatives to using polymorphic associations and one of them is to use the so-called "concrete supertable". From my point of view, this is the neatest solution and is pretty easy ...
1
vote
1answer
277 views

Spliting Datetime into 2 Columns for Restaurant Reservation Schema?

Using PostgreSQL. The primary driver of this is that while no reservation will exist without a date and time, a user can search for and monitor reservations using a time or date or both. With a ...
5
votes
1answer
128 views

“Ranking” values in an ORDER BY clause?

I have the following table: Table "public.employee_employee" Column | Type | Modifiers ...
2
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0answers
797 views

SSL on AWS Postgres RDS

I was reading this: http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_PostgreSQL.html#PostgreSQL.Concepts.General.SSL Step 2 says "Install the certificate in your operating system", but I ...
3
votes
2answers
4k views

pg_dump/pg_restore: different PostgreSQL version, another database name, another tablespace

I am going to move a database from the old server to a new one. the old one runs PostgreSQL 9.1, the new one has 9.3. I want to change the database name. I want the new database to be in a dedicated ...
5
votes
1answer
16k views

Fixing table structure to avoid `Error: duplicate key value violates unique constraint`

I have a table which is created this way: -- -- Table: #__content -- CREATE TABLE "jos_content" ( "id" serial NOT NULL, "asset_id" bigint DEFAULT 0 NOT NULL, ... "xreference" varchar(50) ...
2
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1answer
3k views

Sharding Postgres Database

I have a Postgres database that has grown to the size where it is no longer feasible to store everything on a single database node. There is a Customer table in my schema where each row represents a ...
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3answers
2k views

Indexes for SQL query with WHERE condition and GROUP BY

I am trying to determine which indexes to use for an SQL query with a WHERE condition and a GROUP BY which is currently running very slow. My query: SELECT group_id FROM counter WHERE ts between ...
-1
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0answers
68 views

Bloating effect in Postgresql [closed]

I've done some performance analysis on my DB and I have releved that: Read head 8192 CPU power used 25% Bloating 56% (84GB of 150) 20% occupied by index unused Now I have find that 99% of ...
0
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1answer
3k views

Best Approach to storing chat history?

I'm building a chat application (Yes, another one :P) and am really curious about the best way to store a chat's history(String username, String Message, Time, and possibly string channel depending on ...
1
vote
1answer
331 views

Function quote_nullable(timestamp without time zone) is not unique

When I run this query on "enterprisedb 9.2", it raises an error: select quote_nullable(to_date('09-02-2014 ','dd-MM-yyyy'))::date; Error: LINE 1: select quote_nullable(to_date('09-02-2014 ...
1
vote
1answer
329 views

Compare Number of Rows of Tables

I have two or more tables different by structure and I want to compare their numbers of rows, which I get with the count-star query: select count(*) from table_a For two tables I would like to see ...
5
votes
1answer
790 views

Order by distance

If I have a query returning nearby cafes: SELECT * FROM cafes c WHERE ( ST_DWithin( ST_GeographyFromText( 'SRID=4326;POINT(' || c.longitude || ' ' || c.latitude || ')' ), ...
2
votes
2answers
187 views

SELECT DISTINCT with another table

I want to use distinct to display my data. But I don't know how to do it.This is my code.I want to display table gtest_version field max(poly_version) select distinct on (rule_name) ...
0
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1answer
279 views

Postgres Point-In-Time Recovery with a limited point in time

I'm configuring PostgreSQL WAL-based backup for point-in-time recovery. Actually, I don't really need any point in time beyond 1 month ago and don't want to waste time for the logs older than that. ...
5
votes
2answers
716 views

How can streaming replication be kept lagged by a certain 'delay' time?

Postgres has had streaming replication since 9.0 and since 9.1 it is possible to pause and resume the application of the streamed WAL records using pg_xlog_replay_pause() and pg_xlog_replay_resume(). ...
0
votes
1answer
144 views

How can I get the latest five scores per user per subject?

There is a Postgres table in our system called "scores" which records test scores. It has test takers (users of our system), scores from 0-10, depts and dates each time a test was taken, like this: ...
2
votes
1answer
254 views

What does: ERROR: tuple offset out of range: 0 mean?

It seems (but I can't tell for sure) that after I added a postgis indexed column (USING gist) to my database last week, I have been seeing a lot of those errors: ERROR: tuple offset out of range: 0 ...
0
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0answers
79 views

How large should a database table grow?

I have been experiencing some very slow queries for a specific table. This table grows daily. I ran the pg_relation_size function, which gives the size of a table in the database: mydb=# select ...
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2answers
341 views

optimization of expensive subquery

The following query gets the last report (where latitude and longitude and secs are <> 0) associated with the specified units: SELECT reports.* FROM reports INNER JOIN ...
1
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2answers
155 views

Should I create an index for non key columns?

I have a table in a PostGreSql database defined as following: CREATE TABLE public."MATCH"( "ITEM_A_ID" bigint DEFAULT 0, "ITEM_B_ID" bigint DEFAULT 0, "OWNER_A_ID" bigint DEFAULT 0, ...
3
votes
1answer
262 views

Use of integer instead of interval (of one type)

Our DB design presently has a interval column which will only be storing days (no other interval type) so it is making sense to use INT2 (smallint) instead of interval. Reference to documentation. ...
16
votes
3answers
16k views

upgrading from postgres 9.1 to 9.3 on ubuntu server

I have my production server(ubuntu 13.10) running with postgresql 9.1. I want to use few features of 9.3, hence want to upgrade. Could someone help me with upgrading from 9.1 to 9.3 so that there is ...
3
votes
1answer
776 views

Why does this limit make the postgres planner use a much slower index scan instead of a much faster bitmap heap/index scan?

I have a table of about 700k rows in Postgres 9.3.3, which has the following structure: Columns: content_body - text publish_date - timestamp without time zone published ...