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8
votes
0answers
359 views

Modification to GEQO (Genetic Query Optimization) of PostgreSQL

I need to implement a functionality that is in line with the GEQO functionality of PostgreSQL. I understand that GEQO approach is to encode query plans as integer strings and GEQO generates these ...
7
votes
0answers
436 views

Why is my PostgreSQL ORDER BY case-insensitive?

I have Postgres 9.4.4 running on Debian and I get the following ORDER BY behavior: veure_test=# show LC_COLLATE; lc_collate ------------- en_US.UTF-8 (1 row) veure_test=# SELECT ...
6
votes
0answers
142 views

Surprising results for data types with type modifier

While discussing a recursive CTE solution for this question: Get the last 5 distinct values for each ID @ypercube stumbled across a surprising exception, which lead us to investigate the handling ...
6
votes
0answers
125 views

How to do Statistics in Partial Indexes of PostgreSQL efficiently?

This answer motivated think again my following tables but I am still uncertain how to store variables/results from data analysis for quick selection in post-processing. If stored, I think it is well ...
6
votes
0answers
308 views

PostgreSQL Transaction Committing for hours

I'm running into an issue whereby I have two connections from a user to my PostgreSQL server which have been running for about 4 hours and have been in a commit state for quite some time (at least 1 ...
5
votes
0answers
144 views

To partition or not to partition?

Having already read several questions on SO, external blog posts and manual SO: Foreign Key constraint to partitioned table in Pg dba.SE: Different ways of handling FK to partitioned table in Pg ...
4
votes
0answers
62 views

Using SELECT to call a function in a jdbc migration

I'm looking to set up some Postgres/PostGIS migrations with clojure/jdbc. running side-effect functions with SELECT is proving to be an issue, with most migration libs eventually throwing the A ...
4
votes
0answers
46 views

Use case for hstore

This is the first time (I think) I have the chance to use the hstore data type, but I would like to hear from more experienced folks if what I have in mind is actually a good idea. Now, there's this ...
4
votes
0answers
68 views

PostgreSQL: Add or drop column under load give wrong number of columns errors

I have a heavily used PostgreSQL database. Sometimes I need to add/remove columns, preferably without any service interruptions. I follow the safe operations list from ...
4
votes
0answers
196 views

Storage snapshots for consistent backup of postgresql - different data and log volumes

We are running many Linux VM's in a vmware/shared storage environment, each running its own instance of postgreSQL (a mix of 9.0 and 9.3). Currently, the entire VM sits on a single root ...
4
votes
0answers
537 views

Get inserted row count when master table isn't modified

I have a partitioned table where data resides only in the child tables. The master table has an insert trigger that will distribute inserted data into appropriate child tables. Now, I need to create ...
4
votes
0answers
246 views

ST_GeomFromGeoJSON() Causes postgres to crash

I'm running into a strange problem which I can't solve. The server crashes when executing some postgis related queries. After some debugging, using the examples provided by postgis, it appears the ...
4
votes
0answers
144 views

Postgres multidisk master replicating to single disk slave

I have an odd situation. I have a postgreSQL database master with multiple large tablespaces divided across 3 physical disks. I am setting up a slave that will be used to offload long, ...
4
votes
0answers
7k views

psql: FATAL: sorry, too many clients already

I am suddenly getting this error when either trying to access the website that uses the postgresql database, or even when using the psql utility or pgadmin3. My database is set to handle 150 maximum ...
4
votes
0answers
514 views

PostgreSQL custom operator for equality

I want to build a custom equality operator in PostgreSQL, which can be used in GROUP BY, UNION and DISTINCT [ON] for the json type (just for the sake of curiosity, not for real-world implementation -- ...
4
votes
0answers
2k views

How to properly monitor the number of PostgreSQL database connections?

I tried to use a Nagios script for monitoring the number of database connections on a Postgres database and I reached this problem: these are counted as currently open-connections and measured every 5 ...
4
votes
0answers
531 views

Getting multiple queries with “show transaction isolation level” in pg_activity

I am using PostgreSQL server for my production use. When I fire a query like select * from pg_stat_activity on my server, I am getting 98% of queries like SHOW TRANSACTION ISOLATION LEVEL and ...
4
votes
0answers
110 views

Postgres TupleTable like data structure

I'm writing my own Group by operator (non-hashed implementation) and I'm currently looking on a good data structure to store the result groups. There are two requirement in my mind: the table need to ...
4
votes
0answers
1k views

Is there a Postgres admin GUI that can execute a master file containing multiple sql files

I'm developing a really long script. I'd like to break the script into smaller, more manageable scripts and include each sql file in a master file, then just execute the master file. example: ...
3
votes
0answers
71 views

Some delays in heavy inserts

I have a lightweight web-application with current load of about 500 reqests/sec. Almost each request generates an INSERT request to the database. Some time ago I found that my application has short ...
3
votes
0answers
57 views

Recovery from Live to a new Slave Server - PostgreSQL - ERROR

I've started a new SLAVE PostgreSQL server set up. master: 192.168.100.1 slave1: 192.168.100.2 slave2(NEW SLAVE) 192.168.100.3 * NOTE: I run the pg_basebackup from another STANDBY SERVER. Not ...
3
votes
0answers
97 views

What's the point of prefixing each element in the column by its column number in multicolumn GiN indexes?

According to these slides which, I believe, are incorporated into the current implementation, each column element in multicolumn GiN indexes is prefixed by its column number and is stored separately ...
3
votes
0answers
84 views

Postgresql Strange Characters

I've found a lot of strange characters on data rows like this ÃÃÂà The data inserted by perl script which converting to UTF8 ...
3
votes
0answers
27 views

Understanding row estimation for timestamp in postgresql

PostgreSQL 9.4 I have a table (call it tbl) that's got the column registration_date timestamp. Now, for simplicity I set the following statistic parameter: ALTER TABLE tbl ALTER COLUMN ...
3
votes
0answers
51 views

Roles and policies in Postgresql 9.5 row-level security

Following the the info in posts like these i would like to use the role system and policies, i.e. each user in my system would have a db role. I want to model the following properties but i can't come ...
3
votes
0answers
108 views

Preventing Infinite Trigger Loops in PostgreSQL

I am working with two PostgreSQL databases (one internal and one on our company Web server) where I am attempting to share data between the two instances through the use of triggers. The databases ...
3
votes
0answers
156 views

Form builder schema for SQL database?

There are many ways one can envision the solution, from the top of my head: Two table approach: Field table with (name, field_name, type, description, meta) attributes Form table with (name, ...
3
votes
0answers
50 views

How to deal with large offsets in select?

Table jtest with 200k rows, each row contains jsonb { id: "<uuid>", key: <index> } (<index> is integer 1-200k incremented per each row). There is also btree index on data->'key'. ...
3
votes
0answers
72 views

Optimize PostgreSQL server setting for extremely wide tables

We do have a dedicated server where only PostgreSQL 9.4.4 server is running, 2 physical cores, 16 logical cores, 128GB RAM. On this server we have quite atypical data - there are several tables with ...
3
votes
0answers
56 views

Efficiently computing aggregate functions over subqueries with incremental data

I have a PostgreSQL database (version 9.3.6) containing a large number of orders. As the orders are processed, scan_events are triggered and stored, with multiple events per order. Scan events have a ...
3
votes
0answers
548 views

“could not write to log file, Bad file descriptor” error when working with huge table

I'm having a big problem with a PostreSQL database. Whenever I do something with a huge table (over 9 million rows) the whole postgres process crashes with the following entries in the log file: ...
3
votes
0answers
50 views

PostgreSQL Streaming Replication Tools - Windows

Is there any clusterware available for PostgreSQL clusters running on Windows OS? I'm specifically interested in automatic failover and STONITH functionality. I've done a fairly extensive Google ...
3
votes
0answers
86 views

pg_dump with ssl certificates

I would like to run the pg_dump command from a remote host off my database server that only allows fully verified certificate based connections. How should I go about doing this? The man pages for 9.1 ...
3
votes
0answers
37 views

PostgreSQL/PostGIS: Query seems inordinately time-consuming

I'm doing what I would consider a pretty straightforward query on two tables that aren't huge (~626k records in one; ~47k records in the other). Both tables have GIST indices on their spatial ...
3
votes
0answers
64 views

Recovering data from postgresql xlog

I lost a lot of data in my postgresql database and do not have a dump file to restore backup from, but I heard that in /var/lib/postgresql/9.4/main there are pg_xlog and pg_clog and that those ...
3
votes
0answers
75 views

Flexible and robust way to cull older data?

I am no DBA and that is becoming more apparent daily, as such I am having trouble keeping my query times reasonable. I have about 3.57 Million records ( at about 3.43 GB ) and it takes about 2 minutes ...
3
votes
0answers
152 views

Postgresql upgrade issue

I'm trying to test the Postgresql 9.3 -> 9.4 upgrade process on the development environment on windows and I get weird issue during the pg_upgrade invocation: PS D:\bin\postgres-9.4> ...
3
votes
0answers
483 views

Postgres Streaming Replication: How to re-sync data in master (with standby) after failover

I am absolutely new to postgres 9.1 replication mechanisms. I have managed to set up streaming replication between a master and standby postgres (Both have x number of records). At one point when ...
3
votes
0answers
91 views

Restoring Postgres fixtures into a different database with different premissions

I've got an application called BigSense that uses two database users/rolls. One has full permissions and is used by my application to create/adjust table definitions. Then the application starts with ...
3
votes
0answers
316 views

Slow transactions, many locks

At high load conditions the server app stops responding to client because begin/commit statements are executing very slowly (some take 15 seconds). The queries are simple - insert, update two columns ...
3
votes
0answers
190 views

Recovery when failover

1/ Description: I have 2 Centos machine: master, slave (streaming replication). Both of them are built on PostgreSQL 9.3 (image below) and configured failover event (failover PG 9.3 document). Last ...
3
votes
0answers
130 views

XRC error when trying to access PostgreSQL view properties

I have strange problem, when trying to access PostgreSQL view properties through PgAdmin III: Error: XRC error: 197: invalid row index 1: must be less than 1 After this error is displayed, I am ...
3
votes
0answers
77 views

Can CTE sub-statements be prevented from executing at all?

Through this strategy, time consumed by queries for my application have dropped to extreme lows; however, some queries consume more milliseconds than necessary. The reason why is that upon ...
3
votes
0answers
130 views

Optimizing postgres row overlap constraints involving UUIDs and GIST

For various reasons all my tables have UUIDs as primary keys and I need to exclude duplicate rows where the combination of area_id, user_id, and finished_at <-> started_at window. The only way I ...
3
votes
0answers
379 views

Ways to process XML into a relational structure in Postgres

I have a database that is comprised of ~10 tables, most of which have many-to-many relationships with each other (and an associated join table). I am inserting of the order 100k XML files into a raw ...
3
votes
0answers
701 views

Converting a SQL_ASCII database to UTF-8

I have a postgresql (version 8.1) database that has the encoding set to SQL_ASCII, combined with several apps that some are running using UTF8 and some with LATIN1. With this scope I have a database ...
3
votes
0answers
501 views

Poor performance in my pgpool cluster

I've configured a postgres cluster with pgpool2 using the following link. The replication seems to be ok, but I ran some benchmarks (pg_bench) and the performance is lower than a single node, for ...
3
votes
0answers
555 views

Fastest way to get the length of the intersection of two text arrays in PostgreSQL

This is what I am currently using: CREATE OR REPLACE FUNCTION array_intersect(a1 anyarray, a2 anyarray) RETURNS anyarray AS $$ select array ( select unnest($1) intersect select unnest($2) order by 1 ...
3
votes
0answers
363 views

Stubborn autovacuum process slow things dows

We are facing a strange problem since yesterday. In a database of ours there is a partitioned table containing historical data. That is, every week's data goes to a different partition and stays ...
3
votes
0answers
174 views

What happen when Postgresql tablespace is null?

I'm facing a DWH on postgresql with no DBA (I'm not one) so I turn to you with hope to figure this issue/s. Long story short, when I check the disk usage per tablespace, I get different distribution ...