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1answer
181 views

PostgreSQL replication with periodic log shipping

I'm using Windows Server 2008 R2 with 64-bit PostgreSQL 9.2 on both test machines. What I wish to achieve is that one server will be a master and other will be a slave. This is just for tests, finally ...
5
votes
1answer
398 views

Rounding issues?

Try this: create table test (f float); insert into test values (330.0); commit; select (8 + 330.0/60)::int; --14 select (8 + f/60)::int from test; --14 select (9 + 330.0/60)::int; --15 select (9 + ...
2
votes
2answers
1k views

Are transactions in PostgreSQL via `psycopg2` per-cursor or per-connection?

I'm doing some work with PostgreSQL 9.3 using the psycopg2 database API. I have the DB API set in the minimum isolation level ("autocommit" mode), and am managing my own transactions directly via ...
1
vote
1answer
416 views

What's the best solution for offline db syncing

I'm building a system which requires a master db (BIG master) that contains things like accounts, balances, actions, etc. This db then needs to be accessible at a physical place, like a fairground ...
1
vote
0answers
31 views

Postgres_Failover Not Working

I was able to configure and Replicate between master and Slave ,so when we insert anything on master db it will automatically replicate to slave, Now,requirement is that if we shutdown master can we ...
1
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0answers
466 views

Getting vacuumdb :invalid page header in block error while vacuuming

I am newbie to PostgreSQL and using version 9.2.Disk space for data folder is full causing DB to stop. When i am trying to perform a vacuum to reclaim space, i am getting below error. vacuumdb: ...
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0answers
17 views

Need separate columns that calculates percentage [duplicate]

I have the following table: NAME ------ Alex Bob Bob Tim Alex Roger I need to produce the following: Name Count Percentage ------------------------- Alex 2 33% Bob 2 33% ...
2
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6answers
3k views

Need separate columns that calculate percentage

I have the following table: NAME Alex Bob Bob Tim Alex Roger I need to produce the following: Name Count Percentage Alex 2 33% Bob 2 33% Roger 1 16.6% Tim 1 ...
0
votes
1answer
132 views

Translating MySQL query to PostgreSQL

I have a query which works fine in MySQL, however when I try to recreate the same query in PostgreSQL (same DB structure) I just get a syntax error. MySQL: SELECT ticket.queue_id, queue.name, ...
1
vote
1answer
205 views

UPSERT statement never completes, infinite loop?

Based on some of the stackoverflow answers I wrote the following UPSERT statement, which I think must be stuck in an infinite loop. I added a statement in there to avoid an infinite loop (as it would ...
1
vote
0answers
179 views

listen_addresses does not respect postgresql.conf

I have PostgreSQL 9.3, and I'm trying to set it up on CentOS. One part that has been driving me nuts is the listen_addresses setting. I set it to * inside postgresql.conf: listen_addresses = '*' ...
8
votes
2answers
34k views

psql: could not connect to server: No such file or directory

The error in its entirety reads: psql: could not connect to server: No such file or directory. Is the server running locally and accepting connections on Unix domain socket ...
1
vote
1answer
894 views

Bulk insert in multiple tables

I have two tables on which I perform some bulk inserts: key: key_id(pk), key_name related_key: key_id(fk), related_key_id First Insert: values_data = "($$key_1$$), ($$key_2$$)" INSERT INTO key ...
0
votes
1answer
81 views

API on top of postgresql

I'm looking for one or several API's that can be put on top of postgres to make data input more dynamic. What I'm looking for is something that can handle a wider range of protocols and differently ...
8
votes
1answer
768 views

Adding nullable column to table costs more than 10 minutes

I have problems to add a new column on a table. I tried to run it a couple of times, but after more than 10 minutes running, I decided to cancel the query because of lock time. ALTER TABLE mytable ...
1
vote
1answer
359 views

create trigger hangs

I have a trigger function that just copies inserted values to another table. Then, each night I need to drop and recreate this trigger for some export operation. --trigger function CREATE OR ...
0
votes
1answer
34 views

Separation of users columns in another table

I've got a quite a lot of columns on the users table and I have been cleaning it up recently. Now since I'm searching over the users I figured it would improve performance if I separated verification ...
1
vote
4answers
2k views

PostgreSQL equivalent of MySQL query variables?

Is there a straightforward way to adapt these types of MySQL queries to PostgreSQL: setting variables in MySQL like set @aintconst = -333 set @arealconst = -9.999 It seems not. Assigning ...
0
votes
1answer
290 views

Type of an id field that references another id field

I'm on postgresql. I have a table user (id serial not null) and another table client(id) i need to create a : foreign key client(id) references user(id). What the client(id) type should be? Int or ...
1
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3answers
808 views

postgresql cannot drop a table when autovacuum holds lock on it

Autovacuuming process holds RowExclusiveLock and ShareUpdateExclusiveLock on the table, which I want to drop. I read that autovacuum should be canceled automatically, when submitting DROP TABLE ...
1
vote
2answers
5k views

How do I maintain high INSERT-performance on PostgreSQL

I'm working on a project which is parsing data from measurement files into a Posgres 9.3.5 database. At the core is a table (partitioned by month) which contains a row for each measurement point: ...
0
votes
0answers
169 views

Storing DB credentials in an application source code?

I am making an app which connects to a DB, and the app will have plenty different userslogins. Is it a good design choice to have a specific DB login/password for the application, using which the ...
0
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0answers
52 views

Speed up sorting in this query

I'm trying to optimize the following plan and noticed that PostgreSQL spends a lot of time (relatively speaking) on sorting before the merge joins. Is there a way (using indexes, cluster the table, ...
0
votes
1answer
432 views

What's the difference between INSERT … SELECT and SELECT INTO

Let's say I have a table item and an other one versionned_item. From time to time, I want to copy data from item to versionned_item. What I did is WITH subset AS (SELECT ...) INSERT INTO ...
0
votes
1answer
207 views

What is the best approach to process huge amount of data insertion efficiently

I'm dealing with a HUGE amount of data entry. I need to know the best practice to insert/update table records after new entry inserted in another table. By huge i mean we get more than 2 million ...
1
vote
1answer
454 views

Unique constraint to enforce max one null per item

I am using PostgreSQL 9.3. Suppose we are manufacturing some items of certain types, at any moment we are producing at most one item of a certain type. The following table captures our history of ...
1
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0answers
343 views

How to restore everything (including “postgres” role) from pg_dumpall backup

I have a postgres 9.1 server running and I do backups with pg_dumpall -c -f /nfs/backup/fulldump.sql I'm testing restoring the backup to another server with psql -f /nfs/backup/fulldump.sql ...
6
votes
3answers
38k views

Query to return output column names and data types of a query, table or view

Is there a PostgreSQL query or command that returns the field names and field types of a query, table or view? E.g., a solution if applied to simple SELECT query like SELECT * from person should ...
0
votes
2answers
618 views

How to implement a dynamic string into a (prepared) sql statement?

I have some spatial datasets which are available in a open source metadata catalog software GeoNetwork and in a PostGIS database. The problem is that the student who created the database used ...
0
votes
1answer
185 views

How to predict the growth of a PostgreSQL database

I'm looking for a way to predict growth of the database given its fields, indexes, constraints (as foreign key), number of lines, and so. I searched on Google, but I found only means to determine the ...
0
votes
1answer
33 views

Useful guide & FAQ for Application+SQL [closed]

Of course when you are making your first application for fun it doesn't matter that much how you deal with things. But when you need everything to be up to the current standards you don't always know ...
2
votes
3answers
872 views

Constrain a postgres timestamp to “End of day”?

Given a table named bananas and a timestamp without time zone column named end_time and some psql clients have set timezone to 'UTC' and other psql clients have set timezone to 'US/Eastern' and the ...
1
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2answers
1k views

PostgreSQL get first letter of each word (except…)

I don't think I drank enough coffee today, but stuck on this for some reason. Trying to get the first letter of each word, except a few stopwords. Example "The United States of America" -> "USA" ...
3
votes
2answers
148 views

How to tell which indexes are not being used

Postgresql 9.3 Debian 7 I have a lot of huge indexes in a legacy database I'm trying to optimize. Thinking about dropping all the useless ones, but how can I tell how often they are used and if they ...
0
votes
1answer
156 views

hierarchical retreival of records in postgresql

I am using postgresql-9.2 . I have a table of products which stores the information about the products and its child table is content table , which contains the products linked to it. PRODUCT MASTER ...
1
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0answers
176 views

Multischema view for postgres , querying multiple databases

Im managing SaaS app where each customer has a separate database (Postgres 9.3) . I need to figure out the best way to aggregate and query this data ( READ-only ). I know postgres has problems with ...
7
votes
3answers
13k 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 ...
0
votes
1answer
119 views

Row-level subquery caching?

I have a query that uses a CTE which contains millions of rows. I plan to call this query many times, and the CTE returned each time will have most of the same rows. Is it possible for me to cache the ...
2
votes
0answers
612 views

Stack Depth Limit Exceeded (After delete trigger)

CREATE TABLE parent ( parent_id VARCHAR(30) PRIMARY KEY ); CREATE TABLE child ( parent_id VARCHAR(30) REFERENCES parent ON DELETE CASCADE, child_id VARCHAR(30) PRIMARY KEY ); CREATE OR ...
0
votes
1answer
348 views

Import binary database file into postgres

I have a quite newbie question that I do not know if is possible or not: I had to format my computer, and the only way to keep my postgres database was accessing to data with my folder browser ...
1
vote
1answer
42 views

Index on integer column not helping. Help? (EXPLAIN ANALYZE output inside)

The table market_trades has an integer column market_id which takes values from 1 to 5. This seems like a pretty straightforward query to get the number of trades on each market: WITH markets AS ( ...
1
vote
1answer
58 views

Optimizing a query on a large table (EXPLAIN ANALYZE result inside)

I have a table market_trades with a timestamp column: api_production=# \d market_trades; Table "public.market_trades" Column | Type ...
-2
votes
2answers
73 views

Indexing into two “buckets”

I'm creating a database with PostgreSQL that has an integer field called "delay". All of my queries on this column will be checking if the value of this column is less than or equal to 0, or greater ...
0
votes
1answer
27 views

Determining which database instance makes biggest IO

Assuming that I have a dedicated server on which I am running multiple instances of mysql and postresql servers. How without iotop determine which instance in particular time (proc/pid/io shows data ...
2
votes
4answers
145 views

Make IN clause behave like AND clause

I've asked the same question on stackoverlow, but got no answer, so that's why I'm asking it here (I've read that simple sql questions should be asked at SO, but I have no choice). Suppose I have 3 ...
6
votes
1answer
2k views

PGAdmin III Server Status Error: Could not read directory “pg_log” No such file or directory

Running PostgreSQL 9.3 on Ubuntu 14.04 and pgAdmin III 1.18.1 on Windows 7. I tried Tools->Server Status and I get an error: "Could not read directory "pg_log" No such file or directory" I ...
0
votes
1answer
116 views

How to access pg_settings from separate connection

I am trying to access the pg_settings table from a separate connection belonging to a legacy application. I know how to identify the connection's procid from pg_stat_activity, but I am unsure how to ...
1
vote
0answers
266 views

How to measure bandwidth requirements for MySQL, Postgres, …?

TLTR: how to configure MySQL/Postgres to get a fair measurement of the I/O requirments for analytical queries? Hello, for certain database and especially database hardware experiments for want to ...
2
votes
0answers
9 views

Active record relation AND filtering [duplicate]

(Edit: since reposted to dba.stackexchange.com and answered there). Suppose I have 3 models: Post, PostCategory and Category. I'm implementing some kind of page with filters where I can filter posts ...
4
votes
1answer
1k views

How to optimise window queries in postgres

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