PostgreSQL is an enterprise class, open-source, object-relational database management system (ORDBMS) available for all major platforms including Linux, UNIX, Windows and OS X. Please mention your exact PostgreSQL version when asking questions.

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PostgreSQL Database Data File Integrity Check

When running a PostgreSQL database system how do I know my database as a whole has 100% integrity? Basically how do I know if my data files and pages are all 100% good with no corruption? In the ...
7
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2answers
1k views

Database for building a realtime analytics system

I want to build a system similar to Google Analytics (only used for internal use, less traffic and less feature), and mainly focus on Real time counting of unique URI visit/PV by different ...
7
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4answers
6k views

No NULLs, yet invalid byte sequence for encoding “UTF8”: 0x00

I've spent the last 8 hours trying to import the output of 'mysqldump --compatible=postgresql' into PostgreSQL 8.4.9, and I've read at least 20 different threads here and elesewhere already about this ...
6
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4answers
15k views

Why won't PostgreSQL 9.3 start on Ubuntu?

I have successfully installed PostgreSQL 9.3 from the APT repository on 2 VM's running Ubuntu 12.04 and 13.04...however, I cannot get it to install properly on my host machine running Ubuntu 12.04. ...
3
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2answers
1k views

PostgreSQL maximize performance SSD

I will have a huge PostgreSQL 9.3 database with many tables with more than 100M entries per table. This database will be basically be read-only (once I fill all the necessary tables and build the ...
3
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1answer
2k views

Cannot get my slave - replication server to start

My replication server will not start. I have followed the instructions here: http://opensourcedbms.com/dbms/setup-replication-with-postgres-9-2-on-centos-6redhat-el6fedora/ As well as several other ...
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2answers
4k views

Creating High Availability Cluster with PostgreSQL

I am new to database design. I have a task to create a high-availability cluster. I Googled a lot, however I haven't found any good way to do this on PostgreSQL. Where should I start and what are ...
11
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3answers
1k 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 ...
11
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3answers
475 views

Can IS DISTINCT FROM be combined with ANY or ALL somehow?

Is a postgres way of combining IS DISTINCT FROM with ANY or some other neat way of getting the same result? select count(*) from (select 'A' foo union all select 'Z' union all select null) z where ...
11
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2answers
3k views

Streaming replication and failover on PostgreSQL

I am doing a proof of concept on PostgreSQL replication. After the discussion on forum we decided to go with streaming replication as the performance is good compared to other solutions. PostgreSQL is ...
7
votes
1answer
2k views

Why would you index text_pattern_ops on a text column?

Today Seven Databases in Seven Weeks introduced me to per-operator indexes. You can index strings for pattern matching the previous queries by creating a text_pattern_ops operator class index, as ...
7
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1answer
712 views

Equality query on NVARCHAR column yields multiple results in SQL Server 2012

I am in the process of moving a pet project from PostgreSQL (9.2.2) to SQL Server (2012 Standard). I've noticed an interesting phenomenon when querying unicode words. Given the definition: CREATE ...
7
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1answer
604 views

Is the optimisation fence behaviour of a CTE (WITH query) specified in the SQL:2008 standard? If so, where?

I see frequent references to WITH queries (common table expressions, or CTEs) acting as an optimisation fence, where the server isn't permitted to push filters down into the CTE queries, pull common ...
6
votes
2answers
627 views

What fillfactor for caching table?

I have heavily updated / accessed table where I store serialized java objects. They are in the table for 2-3 hours (also are being updated during that period) and then removed. Size of table is around ...
6
votes
1answer
2k views

PostgreSQL: Unable to run repmgr cloned database

I'm running tests with PostgreSQL hot standby with 1 master, and exactly 1 slave. I am using the instructions on this guide: ...
5
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2answers
2k views

Possible to keep max number of records in postgresql?

Basically part of our Postgresql table is used to keep server access logs, and as such sometimes during production this can get pretty large. is there any way of setting in postgresql to have a ...
4
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2answers
5k views

How to choose a collation for international database?

I'm designing a database which will store data in different languages (using UTF-8), so I think the best way to display the queries results is ordering it according to the user's language during the ...
3
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1answer
157 views

Postgresql 9.3 replication: Preventing wal-files from building up, if receiver goes offline

I have a streaming replication running between two servers. I just upgraded to postgresql 9.3 from 9.2. Earlier on in my 9.2 setup, I have tried that my slave server went offline due to a network ...
3
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2answers
1k views

How do I know what indexes to create for a table

Is there a way I can figure out the best way to know which indexes to create for a table?
3
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2answers
2k views

Running pg_dump on a hot standby server?

Disclaimer: I admittedly haven't tried this yet, but I'm not sure I would know if it wasn't working correctly, so I wanted to ask. I would like to run a nightly backup job (via pg_dumpall) from a hot ...
2
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3answers
5k views

Should I manually VACUUM my PostgreSQL database if autovacuum is turned on?

I use software which makes a big PostgreSQL database (there is a table with a million rows in it) and the developers says I should VACUUM and ANALYZE periodically. But the PostgreSQL database default ...
2
votes
1answer
632 views

Use GIN to index bit strings

I'm trying to extend PostgreSQL to index bit strings up to 1000 bits. (These bit strings are created by quantization of high-dimensional vectors, so for each dimension up to 4 bits are assigned). ...
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2answers
3k views

PostgreSQL stored procedure to return rows or empty set

I have a stored procedure, which RETURNS SETOF ct_custom_type and inside I do RETURN QUERY EXECUTE 'some dynamic query' And I want to do this: If this 'dynamic query' returns >= 10 rows, I want to ...
14
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1answer
24k views

How to use psql with no password prompt?

I wrote a script to REINDEX indexes in a database. Here is one of them: echo -e "\nreindex for unq_vbvdata_vehicle started at: `date "+%F %T"`" >> ${LOG_FILE} psql -U ${USERNAME} -h ${HOSTNAME} ...
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6answers
9k views

Are there any good and free tools for managing a PostgreSQL database? [closed]

Before, I have used phpmyadmin to manage an MySQL database, but now I would like to manage a PostgreSQL database. The PostgreSQL database is on a server, but not a webserver, so I don't use PHP. Are ...
13
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1answer
574 views

Why is there a PostgreSQL Turtle?

I was just checking out the propaganda page for PostgreSQL and I found this little piece of art: It is the "Turtle Style" PostgreSQL logo. How old is this, and did PostgreSQL ever officially use a ...
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2answers
814 views

How can I generate a random bytea

I would like to be able to generate random bytea fields of arbitrary length (<1Gb) for populating test data. What is the best way of doing this?
9
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2answers
22k views

PgAdmin III - How to connect to database when password is empty?

I have installed PostgreSQL 9.1 on my PC (Win 7). I have a small Java application connecting successfully to it with login=sa and password="". The connection works. However, it is refused from ...
8
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1answer
2k views

How to determine if there are [idle connections with] uncommitted transactions in PostgreSQL?

According to a comment on this question I asked about idle connections in PostgreSQL 9.2, some uncommitted transactions (possibly related to some of those idle connections) might cause some ...
8
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1answer
2k views

PostgreSQL pg_stat_activity shows COMMIT

We recently replaced our database server with an upgraded machine with 4 x quad core CPUs and 32Gb of ram. We also repurposed our old box to serve as a slave with streaming replication. Both boxes are ...
8
votes
2answers
609 views

Pros and Cons of Checking if value exist for unique column or let db raise unique error on inserting

While writing a query other day a thought came to me and have stuck in my mind. What is preferable, first checking if a value for a unique column exists and then inserting or insert and let db raise ...
7
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1answer
2k views

MATCH FULL vs MATCH SIMPLE

I've noticed a MATCH SIMPLE or MATCH FULL option in phpPgAdmin, but I can't find a description in the docs. How do they function? The default is set to MATCH SIMPLE.
7
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2answers
4k views

How to do incremental/differential backup every hour in Postgres 9.1?

Trying to do an hourly hot incremental backup of a single postgres server. I have the following setup in postgresql.conf: max_wal_senders=2 wal_level=archive archive_mode=on archive_command='copy ...
7
votes
4answers
1k views

Should I invest the time to change the column type from CHAR(36) to UUID?

I have a few million rows in my database already. I didn't know about the PostgreSQL UUID data type when I designed my schema. One of the tables has 16M rows (about 3.5M to 4 M records per shard), ...
6
votes
2answers
1k views

Slow ORDER BY with LIMIT

I have this query: SELECT * FROM location WHERE to_tsvector('simple',unaccent2("city")) @@ to_tsquery('simple',unaccent2('wroclaw')) order by displaycount I'm happy with it: "Sort ...
6
votes
5answers
12k views

PostgreSQL: The database cluster initialization failed

Both C:\PostgreSQL and C:\PostgreSQL\data have postgres user with full access and admin rights. I ran postgresql-9.1.2-1-windows.exe from postgres user as admin. Target C:\PostgreSQL Every way I ...
5
votes
2answers
181 views

Managing CTE execution order under uncertainty

I am writing a large, multi-step CTE for performance reasons. In one query, data must be moved from one table to another, but the quantity of rows moved is uncertain and could be zero. In a ...
5
votes
1answer
164 views

For alignment optimized table is bigger than original table - why?

In another question I learned that I should optimize the layout from one of my tables to save space and have better performance. I did this, but ended up with a larger table than before and ...
4
votes
1answer
918 views

How do I decompose ctid into page and row numbers?

Each row in a table has a system column ctid of type tid that represents the physical location of the row: begin; create table t(id serial); insert into t default values; insert into t default ...
4
votes
1answer
8k 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) ...
4
votes
2answers
528 views

Order of columns in a compound index in PostgreSQL (and query order)

I have a table with 50K rows. It is actually a PostGIS table. The query has 4 parts (1 mandatory) (3 Optional) intersection box (a geography rectangle) with 4 lat,long (I use st_intersects) ...
4
votes
2answers
2k views

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 ...
4
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3answers
658 views

Full Text Search With PostgreSQL

i have a table with this rows: Stickers ------------------------------------------------------ ID | Title |Keywords (ts_vector) ------------------------------------------------------ ...
4
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2answers
1k views

Importing LARGE quantity of data into a PostgreSQL database

I am importing a large amount of data into a PostgreSQL server (across multiple databases on the server). When I last attempted to import the data, it effectively "crashed" my machine (Ubuntu ...
4
votes
3answers
1k views

How can I write a proper query to JOIN all of these tables without duplicates?

Let's say I have four tables: TABLE: players COLUMNS: id, first_name, last_name TABLE: passing_stats COLUMNS: id, year, passing_yards (several other passing columns) TABLE: rushing_stats ...
4
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1answer
768 views

Database as a service (DbaaS) over dimensions--performance, scalability, & reliability?

MySql Database as a service: Amazon Xeround Another eg. PostgreSQL Database-as-a-Service. You can get the list of similar products here. Does anyone have details on their performance, ...
4
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1answer
1k views

PostgreSQL: Corrupt primary key, inconsistent table

While recovering from a cloud failure, I found that some tables on a PostgreSQL database are behaving strangely. These tables are indexed using a primary key, but a pg_dump yielded duplicate fields, ...
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3answers
3k views

GROUP BY one column, while sorting by another in PostgreSQL

How can I GROUP BY one column, while sorting only by another. I'm trying to do the following: SELECT dbId,retreivalTime FROM FileItems WHERE sourceSite='something' GROUP BY seriesName ...
3
votes
1answer
134 views

How can I achieve clustering of rows without the exclusive lock and logging overhead of the `cluster` command?

The CLUSTER command on a big table can take a long time, and blocks both reads and writes to the table while it runs. I don't need the data in my table to be strictly sorted in index order, I just ...
3
votes
1answer
374 views

2 B-tree indices OR 1 GiST index on tsrange — which will perform better?

I have a table which is storing reservation data using the columns starts_at & ends_at Whenever I'm querying the table to find overlapping reservations, I have an option of using one of the ...