The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
0answers
38 views

MYSQL : Copying to TMP table nightmare

I'm having a (AFAIK) random issue. My server is MySQL and I have a query that is sometimes 10000 times slower as you can see on this screensot : http://snag.gy/vJJ39.jpg The long time occurs during 2 ...
0
votes
2answers
62 views

Postgresql. Generate sets of random integers

With this command I can generate 16384 random integers between 1 AND 200,000. SELECT generate_series (1,16384),(random()*200000)::int AS id I want to generate 10 sets of such integers. Each set ...
1
vote
0answers
58 views

Randomizing the Auto Increment in Mysql

We have a database, where we insert data into table whenever we receive an order from our services. We use auto_increment to generate the ID and assign the order with the same. This is usually same ...
1
vote
2answers
81 views

Perform group by with random group expression (randomly partitioning rows) MYSQL

Let's say I have a table (with millions of rows) cat1|cat2|value A | B| 10 ... and I want to group the data by cat1 and also split the grouping into 10 (at least roughly) equal partitions of ...
1
vote
2answers
145 views

Primary key with randomly varying increments (so it cannot be guessed easily)

I would like the primary keys to be auto-incremented and generated but in varying increments. For ex, if I have increment range as 100... then the auto generated keys would be something like below: - ...
2
votes
1answer
240 views

Create a new table (multiple columns) by selecting random values from an existing table

I am stuck on the following task (PostgreSQL 9.3). Let's say we have the following table1 (which has 10k rows): table1: id 754 800 330 4 59 My goal is to create another table2 with two columns ...
2
votes
2answers
255 views

Set random value from set

I need to put some random values into database, but I don't want to end up with completely randomized text (like 7hfg43d3). Instead I would like to randomly pick one of values supplied by myself.
0
votes
1answer
297 views

Getting MySQL User Variable in Sequence, While Using ORDER BY RAND()

I am running a SELECT statement, which ultimately will be in an INSERT..SELECT statement. I want a result like this ID COUNTER 3 1 7 2 1 3 20 4 12 ...
0
votes
1answer
364 views

MySQL non-sequential primary key of certain length

what's the best way to create a non-sequential primary key of a certain length in MySQL? I'm looking to use the primary key as a 'Pin' number which real actual human people can use to refer to the ...
1
vote
1answer
609 views

Create unique numeric token on PostgreSQL

I have a database where I want to generate unique tokens of six numeric characters. These tokens should be generated each time an invoice number is inserted in the invoice_no column. This would mean ...
10
votes
2answers
710 views

How can I generate a random bytea

I would like to be able to generate random bytea fields of arbitrary length (<1Gb) for populating test data. What is the best way of doing this?
3
votes
2answers
3k views

How to create column in DB with default value random string

Can I create column in DB table (PostgreSQL) which have default value random string, and how ? If is not possible, please let me know that.
2
votes
1answer
386 views

Postgres - how to randomize two columns in a table

I have a table of User data which I would like to disguise/anonymize. Two of the columns have location data (e.g. lat and long, both BigDecimals). I have anonymized all the names and other ...
7
votes
4answers
4k views

How do I do a complex GROUP BY in MySQL?

I have a table that contains several keys into other tables (where each key is comprised of multiple columns). I would like to be able to group rows together that have an equal key, but I don't want ...
4
votes
1answer
3k views

How do I make MySQL auto increment in random order?

I have a table that contains several keys into other tables (where each key is comprised of multiple columns). I would like to create a new column for each key that would be an integer such that ...