Question : For privacy purposes, I need to derive an “Account Number” field that contains a random number, ranging from […]
Tag: random
How to (optimally) get random sample of (a.id, b.id) pairs from two tables (a, b)?
Question : Let’s assume I have to very simple tables CREATE TABLE a(id integer PRIMARY KEY, t timestamp default now(), […]
Detect if `pg_crypto` in Postgres was built with strong random feature enabled
Question : The source code for pg_crypto module mentions an option to build without cryptographically-strong random generation. /* Generate random […]
Obtain different random() values with generate_series() in PostgreSQL
Question : I am trying to generate random data (in volume) and was trying to use PostgreSQL’s random() function with […]
How to Randomly Select a Date?
Question : I am using in a Bash Shell Script this code for retrieving a random date. Is there a […]
How do I make MySQL auto increment in random order?
Question : I have a table that contains several keys into other tables (where each key is comprised of multiple […]
Select random 10 unique rows from MySQL database?
Question : I have one table (questions) with 54 questions. The students have to answer all 54 questions. I have […]
May postgresql’s uuid_generate_v1() conflict when we change the computer date/time?
Question : According to postgresql uuid-ossp documentation uuid_generate_v1() is based on Mac address + timestamp: https://www.postgresql.org/docs/9.4/static/uuid-ossp.html On a distributed database […]
Select random database records between subset of records having the same count(*) in a query
Question : I have this simple query: SELECT `value`, count(*) as `noHits` FROM `topic` WHERE identifier IN (‘” . implode(“‘,'”, […]
Getting MySQL User Variable in Sequence, While Using ORDER BY RAND()
Question : I am running a SELECT statement, which ultimately will be in an INSERT..SELECT statement. I want a result […]