0
votes
3answers
395 views

Performance of primary key IDs with gaps (but in sequential order)

I know that having non-sequential IDs is bad for index performance. But assuming all my IDs are created in correct order, but with large gaps: i.e: 154300000 283700000 351300000 464200000 ...will ...
0
votes
1answer
287 views

Postgresql table with one integer column, sorted index, with duplicate primary key

I want to have a table in PostgreSQL with these properties: One column with an integer Allow duplicates in this column. Duplicates will be rare. Duplicates have no meaning logically and will be ...
0
votes
1answer
38 views

Modify legacy table schemas that have no primary key

I've been tasked with updating our database (SQL Server 2008) so that every table in it has a proper primary key defined. Due to various reasons over the years we have somehow built up some legacy ...
2
votes
2answers
236 views

MySQL - Normalization over meaningless data - Compound Primay Keys or Surrogate ID field

Please forgive my title; if you have a suggestion for it, feel free to comment. I have a database: DROP TABLE IF EXISTS `books`; CREATE TABLE `books` ( `isbn` VARCHAR(255) NOT NULL, `title` ...
4
votes
3answers
562 views

Is a surrogate key better than a natural key in this case

I copied this code from here: CREATE TABLE records( email TEXT REFERENCES users(email), lat DECIMAL, lon DECIMAL, depth TEXT, upload_date TIMESTAMP, comment TEXT, PRIMARY ...
-2
votes
1answer
3k 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 ...
1
vote
5answers
2k views

How should I save apache logs into a mysql table?

This is a php script to view apache logs. I want to save apache logs into a mysql database. Then add some rules for tagging urls using mysql REGEXP search, like: SET tag='some tag' WHERE url REGEXP ...
5
votes
2answers
651 views

Teradata: How to design table to be normalized with many foreign key columns?

I am designing a table in Teradata with about 30 columns. These columns are going to need to store several time-interval-style values such as Daily, Monthly, Weekly, etc. It is bad design to store ...
4
votes
2answers
1k views

Index on primary key not used in simple join

I have the following table and index definitions: CREATE TABLE munkalap ( munkalap_id serial PRIMARY KEY, ... ); CREATE TABLE munkalap_lepes ( munkalap_lepes_id serial PRIMARY KEY, ...
9
votes
4answers
8k views

Mysql int vs varchar as primary key (InnoDB Storage Engine?

I am build a web application (project management system) and I have been wondering about this when it come to performance. I have an Issues table an inside it there are 12 foreign keys linking to ...
4
votes
4answers
440 views

How much will using a varchar(15) PK affect my tables performance?

I am parsing log file lines from a legacy, proprietary application into a nice easy to query DB. The log lines have no unique integer ID. They do have a UNIX timestamp as an 8 character hex string. ...
39
votes
3answers
8k views

Guid vs INT - Which is better as a primary key?

I've being reading around reasons to use or not Guid and int. int is smaller, faster, easy to remember, keeps a chronological sequence. And as for Guid, the only advantage I found is that it is ...