1
vote
1answer
11 views

Joining timestamped records with the most-recent-prior records from another timestamped table

Say I have 2 tables: Table: sales timestamp timestamp without time zone amount numeric Table: prices timestamp timestamp without time zone price numeric How can I get a ...
2
votes
3answers
438 views

How do I ORDER BY typical software release versions like X.Y.Z?

Given a "SoftwareReleases" table: | id | version | | 1 | 0.9 | | 2 | 1.0 | | 3 | 0.9.1 | | 4 | 1.1 | | 5 | 0.9.9 | | 6 | 0.9.10 | How do I produce this output? | id | ...
1
vote
1answer
40 views

Update different columns on different clauses

I have a database table in Postgres 9.3 with the following layout: id SERIAL, col1 INT, col2 INT Whenever a new row is inserted, I will have to update ALL rows col1 and/or col2 in different cases ...
0
votes
2answers
69 views

How can I make this query more efficient?

This is the query: SELECT races.*, tmptimers.last_start_time, tmplaps.updated_at AS last_updated_at FROM races LEFT JOIN (SELECT * FROM timers WHERE timers.user_id = 1) AS tmptimers ON ...
1
vote
1answer
38 views

how to update the value of a period contained inside a bigger range

I have a tsrange like '[2010-01-01 14:00, 2010-01-01 15:00]',20 And want to update the 20 value to 15 in a range inside that, like '[2010-01-01 14:10, 2010-01-01 14:30]',15 My expected outcome ...
0
votes
1answer
37 views

PostgreSQL: schema diff/patch tool

Consider the following setting: A production DB A dev db, on which schema changes are made to enable new features When the development of a new feature is complete, I have to manually update the ...
0
votes
2answers
25 views

assign selected columns to a variable

Select sum(column_a) as a, sum(column_b) as b round(a / b) From table Group by column In the example above I am summing two column, and I would like to use those 2 results in calculating ...
1
vote
1answer
34 views

Does PostgreSQL allow multiple grantees in GRANT commands?

Looking at the PostgreSQL docs it seems that the GRANT command only grants to a single user or role. In fact it doesn't seem to be PostgreSQL alone. Isn't possible to do something like GRANT SELECT ...
3
votes
1answer
11 views

Postgresql query plan differs with limit value making the query slower for lower limits

I have this query: SELECT "table_1".* FROM "table_1" WHERE "table_1"."deleted_at" IS NULL AND "table_1"."table_2_id" = 15797104 ORDER BY "table_1"."id" ASC LIMIT 1 The explain for the query ...
1
vote
1answer
17 views

How to apply a newly-created Domain to an existing Column?

In Postgres 9.4 Beta 1, I successfully created a domain of type VARCHAR, fuel_domain_. The domain checks that a value is any of 5 possible strings, coal, gas, wind, hydro, other. CREATE DOMAIN ...
3
votes
2answers
53 views

Pagination with PostgreSQL 9.3: counting number of pages

I'm implementing pagination and sorting of rows in, let's say, products table, using multicolumn index on category, score and id. -- index create index category_score_id on products(category, score, ...
0
votes
1answer
36 views

How do I select the latest rows for all users?

I have a table similar to the following: => \d table Table "public.table" Column | Type | Modifiers ...
1
vote
1answer
61 views

Efficient way to insert/update/delete table records from complex query in Postgres 9.x

I have this function which returns a set a records and I need to persist those records into a table. I have to do it hundred times a day. My initial approach was just clear data from my table and ...
1
vote
1answer
81 views

PostgreSQL 9.3 - Performance Issue: Counting table entries slower with jdbc postgres driver

I'm using PostgreSQL 9.3 and want to ask if it is possible to improve the performance of my queries based on the following database schema: CREATE TABLE "entities" ( "id" BIGSERIAL, "type" INT ...
0
votes
0answers
34 views

Select script for selecting two columns in a table [migrated]

I need help writing a Select script which selects data from two columns based on a condition. Say I have a table Table: X Columns: ID, Type , and Old_type Column "Old_type" has nulls or historic ...
2
votes
1answer
54 views

PL/pgSQL function or rCTE to detect depth of relations between two tables

I need to perform a PostgreSQL Function for checking the depth of relations. There is a circular binding from table a to b, back to another element in a and, in some cases back again to b. These ...
4
votes
3answers
291 views

Checking whether two tables have identical content in PostgreSQL

This has already been asked on Stack Overflow, but only for MySQL. I'm using PostgreSQL. Unfortunately (and surprisingly) PostgreSQL does not seem to have something like CHECKSUM table. A PostgreSQL ...
0
votes
2answers
60 views

How to change schema so that account_id reference is unique among 3 tables

Original image: Updated to have more-correct terminology and an 'is_debit' column: I am designing a (PostgreSQL) schema for a lottery website that uses double-entry accounting. 'jackpots', ...
1
vote
2answers
65 views

How to construct a set-based query for subset problem?

I have a DB of the following structure (picture shows simplified version) How should I construct a query to get only those recipees, that can be cooked, i.e. for each ingredient in a receipe ...
3
votes
2answers
112 views

How to avoid the SORT operation in SQL query that contains ORDER_BY condition?

I am optimising a PostgreSQL query which involves three tables and a ORDER_BY condition. It seems that PostgreSQL prefer to arrange a SORT operation to perform the ORDER_BY condition, rather than ...
3
votes
2answers
85 views

How to inner join some tables and outer join others?

I'm certain I'm going to be embarrassed by the eventual answer, but I've been googling around and banging my head against the wall and can't figure it out. I have four tables described below. I'm ...
0
votes
1answer
33 views

Demo DB for book on PostgreSQL

The book PostgreSQL: Introduction and Concepts, printed in 2000, was highly recommended to me by the regulars in PostgreSQL IRC channel. However - I was trying to figure out which demo database ...
1
vote
2answers
95 views

How to make a table name an attribute in PostgreSQL?

I have received hundreds of tables in PostgreSQL with identical structure and each containing similar data of a different day, so that the table name is the date of the data. I would like to Union ...
2
votes
1answer
206 views

How to pass a parameter into a function

At the moment I have a view created, see it here in the answer. How can I create a function on that cross tab, so I can pass a date, and get data for the specific date? Also is it a good practice to ...
3
votes
2answers
118 views

Are ORDER BY clause & ROW_NUMBER duplicating functionality when I need top n queries

I have a table that tracks violations for a student. I want to count the number of violations and select top 2 violators from each class. The query would look like this SELECT * FROM ( SELECT ...
4
votes
1answer
132 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 You can refer to this question to see how the query was produced. In the fiddle ...
1
vote
1answer
37 views

Calculate value differences of rows before and after bounded by multiple referenced rows

Supposed I have a user travelling table like this: id | start_time | end_time | location | ----+--------------+------------+------------+ 1 | 1 | 2 | Loc_A | 1 | ...
1
vote
2answers
90 views

Building a Trending query

Is there a way to build a query that returns a record set consisting of a date and the number of records == that date? For example, I have a DB that is tracking inspections that take place on every ...
2
votes
1answer
91 views

Select data based on records created_at column

I have two tables Keywords, ProjectReports: http://sqlfiddle.com/#!15/06ae3/1 As you can see in that example everything works fine, but I want to get more data from those 2 tables and I don't know ...
0
votes
0answers
21 views

Starting up postgres on Ubuntu for the first time

I've installed postgres on ubuntu, created a node and now I'm trying to start up that node as per the instructions: postgres --coordinator -D /usr/local/pgsql/data -p 1281 But I get the following ...
1
vote
1answer
112 views

Very slow simple PostgreSQL query on RDS

I seem to be getting very slow queries on a medium sized RDS box (db.m3.medium, 3.7gb ram). This is across a table of 4,152,928 rows.. select sum(some_field) c from pages where pages.some_id=123 and ...
0
votes
1answer
34 views

PostgreSQL: how do I query over a column with a custom range?

I'm trying to write a query over a string column called grades_served that can have values such as k-5 1-5 5-9 The query could be for a specific grade or it could be a range with a start and end ...
3
votes
1answer
63 views

Query with dynamic ranges in PostgreSQL based on status

We have a table with invoices classified per day, with normal invoices and void invoices (invoices that are voided, in our country we use the Spanish term "anuladas"). For example suppose that we have ...
2
votes
1answer
73 views

MS SQL - export tables to format compatible with PostgreSQL

We're using MS SQL Server 2005 at work and I want to export our data to PostgreSQL for testing. MS SQL Server has an export function but the only one that looks like it would work would be to export ...
0
votes
2answers
70 views

PostgreSQL : select columns inside json_agg

If I have a query like SELECT a.id, a.name, json_agg(b.*) as "item" FROM a JOIN b ON b.item_id = a.id GROUP BY a.id, a.name; How can I select the columns in b so I don't have b.item_id in the ...
3
votes
1answer
44 views

PostgreSQL seems to ignore RAISE EXCEPTION in a CTE

Using PostgreSQL 9.3 I have been trying to define an assert helper function to check for empty query results and similar things as follows: CREATE FUNCTION public.assert ( in_assertion boolean, ...
0
votes
1answer
30 views

Can PostgreSQL results include the query?

I run the following command to run 2 queries in a sql file. Could be 1, could be 50 queries. Depends on the deployment. psql -U <username> -h <servername> -d <databasename> -f ...
1
vote
1answer
62 views

Postgres Update, limit 1

I have a postgres database which contains details on clusters of servers, such as server status (active, standby, etc). Active servers at any time may need to fail over to a standby, and I don't care ...
2
votes
2answers
51 views

PostgreSQL using count() to determine percentages (cast issues)

I'm trying to run the following query to provide the % of records in my patients table that have a value entered in the refinst field. I keep getting a result of 0. select (count (refinst) / (select ...
0
votes
0answers
12 views

Creation of a table with foreign keys in postgres is taking longer time [duplicate]

I am wondering if someone can help me understand this. I tried to add an column to a table of 22000 rows which is referencing other tables(one of these tables have 0.5 million records). It didn't ...
0
votes
1answer
35 views

Postgresql Function Trying to Insert into 1 row instead of 2

Postgresql 9.3, Mac OS X 10.6.7 I created this function and I would like to insert both results into the same row. Obviously the way I have it inserts into 2 rows. First, here is the Table T1: ...
3
votes
1answer
111 views

Optimizing concurrent updates in Postgres

I'm running concurrent Postgres queries like this: UPDATE foo SET bar = bar + 1 WHERE baz = 1234 Each query affects the fixed K number of rows, and I can't find a way to enforce the order in which ...
1
vote
0answers
48 views

Join and aggregate result and insert blanks for missing appendants

Consider these two simplified tables: CREATE TABLE "sources" ( "id" serial NOT NULL, "name" text NOT NULL, CONSTRAINT "sources_pkey" PRIMARY KEY ("id") ); CREATE TABLE "values" ( ...
1
vote
1answer
92 views

SQL hourly data aggregation in postgresql

I am a newbie with database so I'm seeking your help with this one. I have a table containing time series data. 2012/01/01 00:10, 10 2012/01/01 00:30, 5 2012/01/01 01:00, 10 2012/01/01 01:40, 10 ...
1
vote
1answer
30 views

Limit balancing results by a column

I have a web crawler that have a table with tokens to crawl and each token have a fk_location column that is the website where that token must be processed. I also have a function that returns me the ...
1
vote
2answers
55 views

Limiting read access in postgres to few rows

We have a requirement where we want to limit the maximum no. of rows that a select query can return when its done using a particular login. So basically we would like to append a limit clause to any ...
1
vote
1answer
112 views

Have Postgresql query planner use nested loop w/ indices over hash join

I'm having a problem with some StackOverflow-schema related data loaded into PostgreSQL 9.3.4. I have a query that is taking about 10x longer than it should, due to the fact that it is choosing to use ...
18
votes
6answers
661 views

Count where two or more columns in a row are over a certain value [basketball, double double, triple double]

I play a basketball game which allows to output its statistics as a database file, so one can calculate statistics from it that are not implemented in the game. So far I've had no problem caluclating ...
1
vote
1answer
30 views

capability and performance of tags implemented as array vs text vs full text

In terms of search capability and performance, what are the pros & cons of implementing tags as an array or text or full text field? I am seeing limitations of capability in choosing to implement ...
2
votes
3answers
448 views

Change column type from varchar to text in all tables at once

I am using Postgres. I would like to change column type in all tables where column name is "description" from varchar(255) to text. If anyone knows that I would be very glad for your help.