0
votes
1answer
55 views

Best way to add a new column to a large table? (MySQL - MyISAM)

Here's more info on the table that needs to be altered: 15GB size MyISAM table with Index around 5GB Over 100 million rows MySQL 5.1 on RHEL 5 with 4GB RAM Currently live online What's the best ...
0
votes
2answers
36 views

Table size reduce with help changing collation charset [MySQL]

I have table which is big enough, phpmyadmin shows that it takes more than 40Gb space. I can't remove data from it, but I've figure out one thing: there is one field which is described as ...
3
votes
1answer
61 views

Online Schema migration in MySQL : When to start?

I'm the tech lead of a Social Media SAAS, where we're currently experiencing a big increase in data amount we're storing in our mySQL-database. We're having a single MySQL db, and besides many ...
2
votes
1answer
49 views

How safe is it to widen a column in MySQL?

Apologies for the simple question but SQL isn't really my forte, and I want to be sure I don't shoot myself in the foot. A MySQL database I volunteered to help maintain has a table that looks like ...
0
votes
1answer
47 views

Amount of data in a database table

I am trying to run an alter query on a table, and its giving me a Lost connection to MySQL server during query MySQL server has gone away. The query that I am running is alter table table_name ...
1
vote
1answer
92 views

Mysql HY000 the table table_name is full when adding new column

I can't add a new column innodb table which size's 16MB. when I try to add, mysql says HY000 the table table_name is full. I changed my tmp_table_size and heap_size but mysql still says same error. ...
0
votes
2answers
268 views

How long will it takes to rename table

How long will it takes to rename table with a size of 219 GB? This is the specification of our server: Memory: 65 GB Available disk space: 266 GB mysql Ver 14.12 Distrib 5.0.77 Sorry for the ...
9
votes
3answers
420 views

Fastest way to change a 600GB table indexed key datatype from INT to BIGINT

I need to change a datatype from INT to BIGINT in a 600GB MySQL table. The column has a unique index. I might be good with unsigned INT, but I assume changing to that or BIGINT will be pretty much ...
2
votes
1answer
180 views

Alter mysql database engine doesn't work from cluster to other

I got into this issue when I tried to alter my database table engine to InnoDB from ndbcluster, It did not work. But When I changed engine from InnoDB to ndbcluster it worked. It did not throw any ...
1
vote
1answer
492 views

How to change a column type from SET to an ENUM

I have a table with a SET column type that need to be changed to ENUM type. Can I do it with a simple ALTER or will this mess up my data? NB: there are no multiple values (a,b,c) in the table.
1
vote
3answers
4k views

Avoiding “Waiting for table metadata lock” when `ALTER TABLE DROP PARTITION`?

I have some tables that many users need to access to: mysql> show create table v3_cam_date\G *************************** 1. row *************************** Table: v3_cam_date Create Table: ...
1
vote
2answers
153 views

Modify all tables in a database with a single command

Is there a single or a one line command to modify all tables within a database. I would like to issue this command in every table within a database: ALTER TABLE `table_name` CONVERT TO CHARACTER SET ...
0
votes
0answers
33 views

MySQL: optimal configs / methods for ALTER of large MyISAM table to InnoDB (17gb+) [duplicate]

I have a large MySQL (5.1) MyISAM table (13gb table, 4GB indexes - 40mm+ records) I'm going to be converting this table to InnoDB in a production environment. The DB is on a cloud server with ...
0
votes
1answer
176 views

Modify MySQL foreign key related column without dropping foreign key relation

I need to modify a foreign key related column. When I tried to alter it I got "Error on rename of 'x' to 'y' (errno: 150)" error. So I googled and found foreign key relation is the 'villain'. I ...
3
votes
2answers
2k views

How to make a trigger that will compare input with a value of other table?

I had made two tables with the following fields: TABLE 1: "Bookings" FIELD: "fk_flight_number" FIELD: "date_of_reservation" TABLE 2: "Flights" FIELD: "flight_number" FIELD: ...
8
votes
5answers
4k views

Alter table on live production databases

How do most "popular" (MySQL, Postgres...) database system handle altering tables on live production databases (like adding, deleting or changing the type of colums)? I know the correct way is to ...
7
votes
1answer
2k views

How do I swap tables in MySQL?

Suppose, I have a table foo, which contains some statistics that are computed every now and then. It is heavily used by other queries. That's why I want to compute more recent statistics in foo_new ...
1
vote
1answer
79 views

how to use mysql temporal cache tables

I took this example from a book where visitors_today is the cache table from visitor_stored. The idea is to store all the visitors per day (visitors_stored) using a cache table. Create table ...
1
vote
1answer
534 views

Changing collation type database-wide in MySQL

How do I retroactively update the collation type database wide without dropping and recreating it? I accidentally created a database without specifying UTF8 as the default collation type. I then went ...
2
votes
2answers
864 views

Will an ALTER TABLE ADD COLUMN on a slave break replication?

I need to add a last_modified column to a MyISAM table tbl_items. The crux of this problem is that tbl_items houses several gigabytes of data. Also of note, I am using a master-slave deployment with ...
3
votes
1answer
649 views

Preventing replication of alter table command to change engine

I am in the process of switching a MySQL table from MyISAM to InnoDB and I do not want the slave to perform the alter table command until I execute it manually. The intention is to have a backup for a ...
1
vote
2answers
211 views

How to recover previous values in Mysql Table?

I have MySQL Innodb table of 14M rows. There was a coloumn called is_disabled which had different values. By mistake I ran the query without the where clause: update url_queue set is_disabled=1 ...
3
votes
3answers
5k views

MySQL - fastest way to ALTER TABLE for InnoDB

I have an InnoDB table that I want to alter. The table has ~80M rows, and quit a few indices. I want to change the name of one of the columns and add a few more indices. What is the fastest way to ...
3
votes
1answer
2k views

Can I rename the values in a MySQL ENUM column in one query?

Suppose I have a Database table with an ENUM('value_one','value_two'). I want to change that to an ENUM('First value','Second value'). I an currently doing that as follows: ALTER TABLE `table` MODIFY ...
4
votes
2answers
597 views

Preordering the table by a specified column

I have a table and I am always getting the data by ordering a column. In my case, I order by datenum. However, the selection is so slow because of the ordering. Is it possible to order the table ...
5
votes
3answers
4k views

ALTER TABLE on a large table with an indexed column

I have a large table with a VARCHAR(20) column, and I need to modify that to become a VARCHAR(50) column. Typically, performing an ALTER TABLE (adding a TINYINT) on this particular table takes about ...