I have an old database running on a Firebird 2.5 server, on which is missing the collations UNICODE_AI and UNICODE_CI. Direct selection on meta tables is indicating this.
select * from RDB$COLLATIONS where rdb$collation_name like 'U%'
returns UNICODE, UNICODE_FSS, UTF8 and UCS_BASIC.
How can I add these collation to my current database?
Doing a backup restore of the meta table solve the issue.
Related
I need to migrate a mysql table to postgresql.
I need an accent and case insensitive database.
In mysql, my database has the next definition:
CREATE DATABASE gestan
DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
How do I create an equivalent definition to postgresql?
I have read some posts, but it seems outdated.
create database getan
encoding = 'UTF-8';
There is no direct equivalent for the case insensitive collation _ci in Postgres.
You can define a new ICU collation that uses case insensitive comparison, but it can't be used as a default collation for a database, only for the collation on column level.
Related questions:
Install utf8 collation in PostgreSQL
https://dba.stackexchange.com/questions/183355
https://dba.stackexchange.com/a/256979
I have a Postgres 9.3 database which, by mistake, has been set to:
but I need it to be:
Since the Encoding doesn't change, it is safe to dump the DB and restore it later (see here) to a database with the new Collation / Character type?
Perfectly safe -- the collation is just telling Postgres which set of rules to apply when sorting text.
You can even set it dynamically on a query basis in the order by clause, and should be able to alter it without needing to dump the database.
I'm using postgreSQL 9.1
I've set the Collation and the Character Type of the database to Greek_Greece.1253 and I want to change it to utf8
To change the collation I should use this, right?
But how can I change the character type?
Thanks
EDIT
I ment to wright C instead of utf8. I would like to change the Collation and the Character Type to C
You cannot change default collation of an existing database. You need to CREATE DATABASE with the collation you need and then dump/restore your schema and data into it.
If you do not want to recreate the database - you can specify collation for every text collumn in your db.
Here is detailed postgres manual on collations: Collation Support.
First line of this manual page states:
LC_COLLATE and LC_CTYPE settings of a database cannot be changed after
its creation.
CREATE DATABASE, pg_dump, pg_restore
How can I set case insensitive collation for the whole database?
Do I have to recreate the tables and data?
Database is firebird 2.5
Quote from the release notes:
The character set and collation of existing columns are not affected by ALTER CHARACTER SET changes.
So yes, it seems that the best way would be to recreate the database with desired default character set and collation (and / or with explicit definitions in domains).
A DB2 for z/OS database has been setup for me. Now I want to know the encoding scheme of the database and change it to Unicode if the database is other type of encoding.
How can I do this? Can I do this using dynamic SQL statements in my Java application?
Thanks!
You need to specify that the encoding scheme is UNICODE when you are creating your table (and database and tablepsace) by using the CCSID UNICODE clause.
According to the documentation:
By default, the encoding scheme of a table is the same as the encoding scheme of its table space. Also by default, the encoding scheme of the table space is the same as the encoding scheme of its database. You can override the encoding scheme with the CCSID clause in the CREATE TABLESPACE or CREATE TABLE statement. However, all tables within a table space must have the same CCSID.
For more, see Creating a Unicode Table in the DB2 for z/os documentation.
You are able to create tables via Java/JDBC, but I doubt that you will be able to create databases and tablespaces that way. I wouldn't recommend it anyway, I would find your closest z/os DBA and get that person to help you.