In relational database design, a primary key can uniquely identify each row in a table. A primary key comprises a single column or a set of columns.

learn more… | top users | synonyms

0
votes
0answers
50 views

redshift performance effect if use 32 character long unique string as Primary key instead of auto incremented int

In my analytics application I am creating 32 char long unique string for each hit as user_session. In current implementation, I am storing user_session in tbl_sesssion in session column and I am ...
0
votes
0answers
216 views

PostgreSQL replace primary key and converting non-serial to serial type

I'm basically building my own version of phpPgAdmin (if I get good enough to make it good enough I'll post it on a repository hosting service) and currently I'm revising my primary key tool to replace ...
0
votes
1answer
226 views

Prevent Primary Key increment when an INSERT statement fail in PostgreSQL

I have a simple table in my PostgreSQL database like this: CREATE TABLE person_type ( id serial NOT NULL, name character(55) NOT NULL, CONSTRAINT person_type_pkey PRIMARY KEY (id), CONSTRAINT ...
0
votes
0answers
180 views

Using partitioned table, and dealing with auto_increment PK

I have a big table (>100 million rows) that tracks user's activities. It has an ID, which is PK and has auto_increment property. This is the only unique key. Table also has userid and datetime column. ...
0
votes
0answers
50 views

MySQL on Server side PRIMARY KEY taking automatically random Id

I have problem in my database which i have uploaded in Database Version libmysql 5.1.73 In that i got problem like one PRIMARY_KEY field incrementing random values. inserted id's like 1, 2, 35, 67, ...
0
votes
0answers
18 views

Setting the Relationship as a Continuous Line Without Changing the Qty INT into Primery Key on SQL

Now it is required to make the following database. In the following, if I tick the checkbox of "Identifying Relationship", the line will become continuous line but the key type will also be ...
0
votes
0answers
62 views

SqlServer: can one table's PK be the FK of two table's?

I have three tables project, users and proj_user. The PK of proj_user table is the FK of project and users table's pk e.g.(project_id,user_id) My question is, is it possible if the project_id and ...
0
votes
1answer
27 views

persistence entity with composite key

I have class named 'User'. It has the following properties firstname lastname mobile email pin I want to design a table or hibernate entity that will have unique email for each row; the same for ...
0
votes
0answers
114 views

Auto increment holes in primary key - any issues?

I have an application that is creating large holes in the auto incremented primary surrogate key to the table as it uses lots of INSERT ... ON DUPLICATE KEY UPDATE queries. I'm looking into changing ...
0
votes
1answer
38 views

Database relationship refresher

All, After several years of programming applications, I'm looking to refresh my understanding of databases. What I knew to begin with was fairly basic, and honestly, it's disappeared over time. I ...
0
votes
2answers
46 views

primary_key problem in MySql view

I have 3 tables. and I want to create a view. There is no problem about generating SQL qeury and creating a view. but when I want to use this view in my web app it says me (LIKE THIS): "your view's ...
0
votes
0answers
22 views

Should a surrogate key reflect one of my columns? [duplicate]

I currently have a column called LoadID which is a surrogate key that just increment by max()+1. I also have LoadNumber which always seems to have the exact same value of LoadID, since they will ...
0
votes
0answers
25 views

Impact of additional int field as primary key

Directly to the point, at one time I have a table like this: create table item( item_id varchar(50), constraint pk_item1 primary key (item_id) } However from my discussion one day, there is ...
0
votes
0answers
115 views

Overcoming the HDD IOPS limits on a billion row table? Is getting SSD the only solution?

I have a table with this structure: CREATE TABLE `requests` ( `userid` int(11) NOT NULL, `messageid` int(11) NOT NULL, `queueid` int(11) NOT NULL AUTO_INCREMENT, `problem_id` int(3) NOT NULL, ...
0
votes
0answers
679 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 ...
-1
votes
1answer
319 views

SQL Server: performance of IDENTITY vs INT as primary key

The most important table of my database is about 300,000 records, and growing. More than 20 tables have a FK to it. Its primary key is a number, but for historical reasons is defined as nvarchar(6) ...
-1
votes
2answers
85 views

Question about choosing primary key

My scenario is that I have a super type named PERSON and two sub types EMPLOYEE and CUSTOMER. I use the Primary key from PERSON, PersonID, in both EMPLOYEE and CUSTOMER as foreign keys. However, I ...
-2
votes
1answer
5k views

What are performance benefits when using number type instead of using char/varchar?

From various posts, I have summarized about using number type instead of char/varchar for PK: If you choose char/varchar type for PK and your values are short (just some alpha numberic codes) then it ...