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
35 views

postgresql bigserial or sequence using jpa

I'm a java developer working with jpa, before to define the indexes in my entities i would like to known which one is faster o better to use?.
0
votes
0answers
20 views

Organizing a couple tables in postgresql

I have a data structure that is represented like this: { 'question_id': 1, 'is_required': False, 'question_text': [ { 'id': 1, ...
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
91 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 ...
1
vote
1answer
41 views

Spliting Datetime into 2 Columns for Restaurant Reservation Schema?

Using PostgreSQL. The primary driver of this is that while no reservation will exist without a date and time, a user can search for and monitor reservations using a time or date or both. With a ...
1
vote
1answer
56 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) ...
0
votes
1answer
104 views

Best Approach to storing chat history?

I'm building a chat application (Yes, another one :P) and am really curious about the best way to store a chat's history(String username, String Message, Time, and possibly string channel depending on ...
1
vote
1answer
53 views

Best approach on storing/displaying sanitized data

Surfing the web I find two approaches on storing data in databases. Approach 1: Store data in the database with the html-specialcharacters sanitized $userdata = $_POST['field']; ...
0
votes
1answer
91 views

Choosing between single table and multiple table database scheme

I'm building an application which saves addresses in a PostgreSLQ 9.3/PostGIS 2.1.1 database. Currently I am trying to find an efficient database schema, so far I've come up with two that would ...
1
vote
2answers
88 views

To normalize or not to normalize for few distinct values

Assuming in a Postgres database, you have a table called party, which can have less than 5 well-defined party_types such as 'Person' or 'Organization'. Would you store the party_type in the party ...
3
votes
1answer
48 views

Non-overlapping rectangles constrained to a boundary

I am trying to model placement of parts on a circuit board. Without any meaningful constraints, my basic schema looks like this: create table part ( part_id bigserial primary key, name text ...
2
votes
2answers
92 views

Most performant way to fetch last record

I have a Postgres table Prices with the columns price (Decimal) product_id (Int) Prices get updated regularly and I keep old prices in the table. For a given product, the last price in the table ...
2
votes
1answer
87 views

Enforcing constraints “two tables away”

I ran into some trouble modeling an electrical schematic in SQL. The structure I'd like to capture is part ←────────── pin ↑ ↑ part_inst ←───── pin_inst where "inst" is short ...
5
votes
1answer
74 views

Hierarchical structure with limited number of records per user

I am planning schema for an affiliate network. For all hierarchical queries I am using Postgres tablefunc extension but here is another problem. Any user can refer only 3 other users at max. So for ...
3
votes
0answers
75 views

Storing and querying rolling data in PostgreSQL

I have a large quantity of weather model data being put into a PostgreSQL database. The machine has 8 cores and 16 GB of RAM. I'm running PostgreSQL 9.3 with PostGIS 2.1. Each table will have a ...
3
votes
1answer
60 views

Geographic Synonyms

Let's say I have a table representing principal country divisions (ex States): create table principal_country_divisions ( id int primary key, name text not null, country_code char(2) ); insert ...
2
votes
1answer
81 views

Two-column foreign key constraint only when third column is NOT NULL

Given the following tables: CREATE TABLE verified_name ( id SERIAL PRIMARY KEY, name TEXT NOT NULL, email TEXT NOT NULL, UNIQUE (name, email) ); CREATE ...
2
votes
1answer
102 views

Need for indexes on foreign keys

I'm struggling with indexes, primary keys and foreign keys... And the need of having them all. If I have two tables, both of them have an integer as a primary key. The first table references ...
0
votes
2answers
79 views

Database design for holding read/unread content state

In forum application I have member table and post table. What I need is to keep track of what posts have been read by which members. What I thought about is to have a junction table with two columns: ...
0
votes
1answer
49 views

Nullable One To Many w/Join Table - Indexing

I have a question regarding database design, I am working with PostgreSQL using Hibernate for ORM, the design I inherited includes the following tables users user_id (pk) user_name user_dob ... ...
0
votes
1answer
118 views

How can you have a combined primary key for one table?

I have exactly the same question as posted here. But in my case I do not use MySQL but Postgres. Can this be done with Postgres? All things indicate I can not use a combined index in Postgres, so ...
2
votes
1answer
95 views

PostgreSQL 9.2 tstzrange null/infinity CONSTRAINT CHECK

I'd like to limit a PostgreSQL 9.2 tstzrange to valid dates at both ends. No NULLs nor 'infinity'. Various revisions of this SQL isn't constraining '-/+infinity' input: CREATE TABLE bill ( id ...
1
vote
1answer
200 views

Design DB for users with different information fields?

Let's say I want to register all faculty of a university and they are in different fields and have different resume information. Here we have some common fields and some field specific fields. for ...
2
votes
3answers
229 views

Many to many link tables with history? [closed]

While creating a PostgreSQL database of customer subscribed services with DNS domains, I want to: enable customers to subscribe to multiple services each service can have multiple domain names per ...
0
votes
1answer
112 views

Entity with >150 attributes: One table or many tables with relationships

I have entity with 170 attributes. It's data from vehicle monitoring. Every entity has datatime label and unique id of gps terminal. Datetime and id of terminal - these are conditions for GROUP BY ...
0
votes
2answers
189 views

Which schema is better for a shopping project? [closed]

I'm working on a business-to-customer project that has variety of product types. There are a few properties like name, description, brand_id that each product has but there are also many specialized ...
1
vote
1answer
1k views

Postgresql vs MySQL - Which is better for join queries & writing data(inserts) [closed]

I have to design a database which will end up with 50M records in a single table(there will be other tables with lesser number of records). I'm more concerned with join queries & writing ...
0
votes
1answer
48 views

Creating groups and members [closed]

Is this a good idea to manage members of a group like so: *Assuming members can belong to one group and no other *Simplified model Group: name someid User: name ForeignKey(Group) state ...
-3
votes
1answer
74 views

Make “NOT NULL” default in Postgresql 9.2 [closed]

I use NOT NULL a lot when creating columns. Is there a way to make this default when defining columns? In other words, make column is_nullable default to NO. (I realize this would make it harder ...
3
votes
2answers
947 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 ...
1
vote
1answer
231 views

Best practice for storing record metadata

What is the best practice for storing metadata of individual records in a database? I need to store common meta data such as creation time and time of last update for many tables in my database. I ...
0
votes
2answers
112 views

Mirrored tables on PostgreSQL

I have some values under "account" and I need to have the same values under "invoice", so, I'm trying to find a way to symlink my tables, so every time one gets updated, the another have the new value ...
0
votes
0answers
64 views

How do I model the database for an application containing canvases which are divided into building blocks?

How should I model my database if I wanted to have this functionality: I want to be able to create a canvas which has many building blocks (they are something like it's sections). There are many ...
2
votes
4answers
783 views

Database design - People and Organisations

Databases are not my primary skill and I am finding I need some assistance please. The software we are building has "Customers". The Customer could either be a Person or an Organisation. I really ...
1
vote
1answer
166 views

Table for optional parent/child relationship

Assuming we have the following table: Item, Parent, Child and Parent is the parent of child. The item can either belong to a parent or child and not both. I have other tables that are similar to ...
4
votes
2answers
334 views

Is it ever a good idea to denormalize for integrity?

I'm using Postgres 9.2 to develop a quiz app, in which I present the user with a series of problems and record their answers. These problems can take a variety of forms - they might be multiple ...
2
votes
2answers
253 views

How to implement posts with “seen by” like facebook?

Inside a Facebook group there is a feature when every time see the group newsfeed it mark all posts as seen by me. And if I see a specific post inside a group thought a url ...
4
votes
1answer
500 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 ...
5
votes
1answer
1k views

Could too many idle connections affect PostgreSQL 9.2 performance?

Some queries on my database server seem to take a long time to respond, and I believe the CPU usage is high. When running ps aux, I see ~250 "idle" connections (which I believe to be too many). I ...
2
votes
0answers
120 views

How to execute a non-table-locking update operation on PostgreSQL? [closed]

Looking for a good way to update the value on a column for all the rows in a database (not huge, but big enough - about 10M records), without locking the whole table, so operations can continue while ...
5
votes
1answer
267 views

How does PostgreSQL physically order new records on disk (after a cluster on primary key)?

Need to know how PostgreSQL orders records on disk. In this case, I would like to take advantage of index combination as stated in the docs, which as I understand uses bitmaps to get matching rows ...
3
votes
1answer
49 views

Does avg_query for PgBouncer include update and inserts?

Trying to tune our application and would like to know if the stats data that pgBouncer shows as avg_query, according to the PgBouncer docs on usage: avg_query Average query duration in ...
4
votes
1answer
414 views

Will table inheritance in PostgreSql suit this situation?

Let's start off by saying, I'm new to PSQL and coming from a MSSQL background. I'm starting to design a DB in PSQL. So my main aim is to have a Main schema in this DB, which I am going to use to ...
6
votes
1answer
128 views

What is a good way to determine the performance I should expect from a PostgreSQL server?

Trying to figure out how I should expect my database to perform. Basically, I need to determine when the server I have set up is reaching its performance limits - which would help me plan server ...
4
votes
1answer
275 views

Does PgBouncer create a separate pool for every database config entry?

If I set up a pgbouncer.ini config file with several database entries, does pgBouncer create a separate pool for each one? I would think so, but have not been able to confirm this. For example, ...
5
votes
2answers
351 views

How to properly configure PostgreSQL RAM usage?

Using PostgreSQL, we have several hundred concurrent processes doing regular database access. We have our data spread out through several database servers, each of which houses a connection pool with ...
2
votes
0answers
263 views

How to properly configure pgBouncer transaction level pooling?

What is a good way to determine the number of available transaction connections when using pgBouncer to pool database connections? Also, how should I determine the number of max_connections and ...
0
votes
0answers
308 views

Postgresql Retrieve / Find Primary Key Serial Autonumber field for Audit logs

I need to find the Primary Key field name in each of a number (approx 70) of tables to create audit logs. All the primary keys are type serial (auto incrementing integer) and all have the name in the ...
7
votes
3answers
684 views

Store a formula in a table and use the formula in a function

I have a PostgreSQL 9.1 database where part of it handles agent commissions. Each agent has his/her own formula of calculation how much commission they get. I have a function to generate the amount of ...