1
vote
1answer
64 views

Difference between now() and current_timestamp

In PostgreSQL, I use the now() and current_timestamp function and I see no difference: # SELECT now(), current_timestamp; now | now ...
1
vote
2answers
32 views

Returning empty string when string_agg has no records

I am trying to return a text field in a PostgreSQL query that is of the form 'stringOne' || string_agg(field, ',') || 'stringTwo' where for certain elements in the group clause, field is always ...
2
votes
1answer
25 views

How to create function(table_name) that returns a set of the table

I have a set of tables that share the same fields (some timestamps and users names used for version control). I need to create a function with dynamic sql that uses a table_name and a timestamp as ...
0
votes
1answer
18 views

Merge left outer join column

I have a query that use left outer join. something like that : select issues.id, journal.notes from issues left outer join on (issues.id = journal.issue_id and journal.notes != '') So far it ...
1
vote
1answer
41 views

Unnest multiple arrays into rows

I have been shown a great way to bulkinsert with this example: WITH p AS ( INSERT INTO parent_table (column_1) SELECT $1 RETURNING id) INSERT INTO child_table (parent_table_id, ...
0
votes
1answer
30 views

Postgresql condition on subquery results

This is a new question based on the solution to my previous question I have the following tables: users int (pk) user_id date last_visit int (fk) local_site sites int (pk) site_id site_stats ...
2
votes
1answer
36 views

Tuning Postgres for Single connection use? Or is postgres wrong tool?

Any rules of thumb for work_mem, maintenance_work_mem, shared_buffer, etc. for a database that DOESN'T anticipate concurrent connections and that is doing lots of aggregate functions? I'm a social ...
2
votes
1answer
31 views

How do I sort the results of a recursive query in an expanded tree-like fashion?

Let's assume you have a nodes tables like this: CREATE TABLE nodes ( node serial PRIMARY KEY, parent integer NULL REFERENCES nodes(node), ts timestamp NOT NULL DEFAULT now() ); It ...
2
votes
2answers
92 views

How slow is slow in postgres?

I'm working with postgres for the first time. I have a lot of experience with small / medium size data analysis (i.e. things that fit in ram and can be analyzed in R, Stata, Matlab, etc.), but am now ...
1
vote
1answer
77 views

What's better here - a single column or multicolumn primary key?

Let's assume you have a table groups and a table item. Each item belongs to exactly one group. It is an inherent part of that group. An item cannot exist outside of a group and it cannot be moved to ...
0
votes
1answer
28 views

PostgreSQL extending UPDATE query

I have the following update query to populate a table storing user stats users: int (pk) user_id date last_visit int (fk) local_site sites: int (pk) site_id site_stats: int (fk) site_id ...
1
vote
1answer
37 views

Select query for returning different data based on creation time

I have a view, which will Select data from table reports the select will filter the data based on multiple dates. reports table: id, key_id, position, created_at My select: pr.key_id, ...
-1
votes
2answers
46 views

Select records for a day and a day - 1 day

From one table, I want to get the records from one column position when the created_at = Today and when the created_at = created_at - 1.day COALESCE(array_agg(DISTINCT pr.position)) AS position, ...
3
votes
1answer
84 views

How to implement business logic permissions in PostgreSQL (or SQL in general)?

Let's assume I have a table of items: CREATE TABLE items ( item serial PRIMARY KEY, ... ); Now, I want to introduce the concept of "permissions" for each item (please note, I'm not talking ...
4
votes
2answers
77 views

select specified number of unique IDs where second column is unique

Look at the following example starting from the top row (id=9) and work your way down, selecting a limit of 4 rows that have sec's that we have not yet seen. We "select" id=9 because we don't yet have ...
3
votes
3answers
184 views

Join table on some conditions

I've got a table called activities. And a table messages. Activity has many messages, and one message has one activity. This are the message columns : id sender_id receiver_id body activity_id I'm ...
1
vote
1answer
50 views

Consolidating large table

I need some help with a complex query. Table def: Table "public.agent_log" Column | Type | Modifiers ...
2
votes
2answers
71 views

Problem translating MySQL to PostgreSQL

We're using Trac for issue tracking. I migrated it from MySQL to PostgreSQL, but some of the ticket queries no longer work. In the below, all I did this far is replace IFNULL() with COALESCE() and ...
1
vote
1answer
31 views

RETURN NEXT in Postgres Function

I'm currently writing a plpgsql function that will select from a table and produce a substantial amount of data. I was originally going to return an array, but I found a resource that explains the ...
1
vote
1answer
43 views

select and count based on a condition

I have two tables, proj: id name and proj_reports: id, position, created_at, key_id, proj_id and I want to select from key_reports for each proj_id: `- total number of `key_id` which can be done ...
0
votes
0answers
41 views

Reduce read write delays in specific database setup

I have a database with a large table with 15 columns (type double). It contains a large amount of data (~ 100 rows of data for every second. Holds 3 days of data). I also have a real-time program that ...
2
votes
6answers
92 views

Efficiently storing irregular/repeating intervals (think calendar/events)

I am developing a service that relies on users being able to recieve messages that they themselves choose. These messages need to be stored somewhere before they are send for processing. Right now ...
0
votes
1answer
39 views

Postgresql Database on external HD

I'm completely inexperienced with PostgreSQL, but have to do some work on it, and I have been googling for a solution for almost two days. I hope someone here can help me out. I have a PostgreSQL ...
0
votes
1answer
47 views

Add 0 into array_agg if there is no matching data

I wrote this view, and it is selecting almost everything I want, but I do not get results for all: project_keywords(which has_many project_report(keyword_id, project_id)) So a project_keyword has a ...
1
vote
1answer
60 views

Postgresql view how to do the query

I have 4 tables: Project: id name Keyword: id, name ProjectKeyword: project_id, keyword_id (project has many keywords, keywords has many projects) ProjectReport: project_id, keyword_id, ...
2
votes
1answer
59 views

Postgresql subquery speed much slower than individual queries

In Postgres 9.1. I am attempting to do a single query to get the timezone of a given postal code. I have data loaded in my database, and I am using PostGIS to store the coordinates of each postal ...
2
votes
2answers
71 views

Postgresql: Query across schemas

I have multiple schemas that I need to query across. The schemas are not know in advance for example: U111 U222 U333 I need to select across these three schemas from a specific table in each of ...
1
vote
1answer
45 views

Aliases with correlated subqueries

I am looking at an example of correlated subquery with aliases from a PostgreSQL book: bpsimple=# SELECT * FROM orderinfo o, bpsimple=# (SELECT * FROM customer c WHERE town = 'Bingham') c bpsimple=# ...
3
votes
2answers
38 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
vote
1answer
72 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 ...
0
votes
2answers
63 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
votes
1answer
92 views

“Ranking” values in an ORDER BY clause?

I have the following table: Table "public.employee_employee" Column | Type | Modifiers ...
4
votes
1answer
83 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
73 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
votes
1answer
42 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: ...
10
votes
3answers
382 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 ...
2
votes
1answer
129 views

What is the difference between MySQL and PostgreSQL in terms of writing SQL queries? [closed]

Other than performance and security is there really any difference between MySQL and Postgres like SQL queries, built-in functions, procedures and so on? I'm asking this because I'm familiar with PHP ...
1
vote
1answer
44 views

complex update query postgres

I've got a bunch of ids from table messages and I want to update the table activities. This is how I imagined my query would work (so you get better idea what I'm trying to accomplish): update ...
4
votes
2answers
114 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) ...
0
votes
0answers
53 views

Postgres vs MySQL Database Maintenance

I have been using Postgres and MySQL for a long time now. There are a few routine maintenance chores that must be performed on a regular basis to keep a PostgreSQL server running smoothly. As as ...
1
vote
2answers
41 views

Nearest value for each foreign key

I have a table with a primary key, timestamp, value, foreign key. I would like to find the nearest value to a timestamp for each of the foreign keys in a list. Unfortunately, the gap from the given ...
3
votes
1answer
70 views

Postgresql query slowed with table growth

I have a very simple table in Postgresql, and need some guidance to speed up my queries. Recent large expansion of the data in the table has made everything grind to halt. Table body_feature: ...
1
vote
2answers
48 views

SQL Select query with postgresql

I'd like to find all rows if is shows even once a particular value with postgresql For example : id TIT_CODE CLI_NOM CLI_PRENOM CLI_ENSEIGNE 1 M. DUPONT Alain A 2 M. ...
2
votes
2answers
128 views

UPDATE table with another table data

I want to update the table car_check field fencing.(total 40 rows).I also use postgis function. I think it's a little difficult.Any suggestions? The code is the first carid example. UPDATE car_check ...
2
votes
2answers
74 views

Order of returned record with IN statement postgres

I know that the order of returned records is not guaranteed with the IN statement for Pstgres. For example if I do this: SELECT "users"."id" FROM "users" WHERE "users"."id" IN (13589, 16674, 13588) ...
0
votes
0answers
20 views

postgres database program to save sql templates and search where used it

I have a postgres database with tables and functions build using sql templates. And I would like to use a database program to save these templates and search where I used it. What i want to do is to ...
1
vote
1answer
43 views

Selecting distinct records

I have a user relation to address (1 to 1). So the address has two types which is a type column. One is the VerifiedAddress and the other one is the SearchAddress. So the user who had verified his ...
1
vote
1answer
78 views

Optimizing Postgres query

I've got a one to one relation from users to addresses table. Where one user can have one search address and one verified address. I've got two indexes on addresses table : Index on state field ...
2
votes
1answer
32 views

Understanding postgres reason for picking this query plan

I ran a query: select * from orderline where orderid = 12345 and status > 0 that gave me the following plan: Bitmap Heap Scan on orderline (cost=286370.00..531410.78 rows=76372 width=155) ...
2
votes
1answer
42 views

redundant foreign keys in PostgreSQL - are there any indexing benefits?

Note: this is not the same as this SO question which is about adding redundant information in the tables themselves. Does the final statement in the below series of statements buy me anything in ...