Обсуждение: migrating from mysql
Hi everyone, I am new to postgresql. I am planning to migrate our current database (mysql) to posgresql. I am currently having difficulties dealing with the order of the tables that is created. Here is what I do: 1. I use myqsldump to get the schema and data. 2. I use my2pg and a java utility I created to convert mysqldump to sql statement that is understood by postgresql. 3. When populating the data to postgresql, it complained relation "xxx" doesn't exist. This is the case because the table that is refrenced has not been created. The quick fix to this will be to change the sequence of the tables that are created in such a way that tables that are being referenced are first created before referencing table. However, this is not practical if we have many tables. My questions is: is there a way to get around this? is it possible to disable checking for relation when creating a table that is referencing to other tables? I've searched around the internet and found somebody mentioning about disable-fk-verifications, but I got an error (something like invalid configuration parameters). I am currently using postgresql 7.4.6. Any ideas/suggestions is greatly appreciated. J
1. Create a script that creates the tables without RI stuff like foreign keys and triggers. 2. Import the data into the tables using COPY 3. Create the RI stuff with 'alter table' and 'create trigger' statements http://www.postgresql.org/docs/current/static/sql-copy.html http://www.postgresql.org/docs/current/static/sql-createtrigger.html http://www.postgresql.org/docs/current/static/sql-altertable.html As long as the original tables have no RI problems, and you load a snapshot of the existing MySQL data, you should not have any problems. -----Original Message----- From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Junaili Lie Sent: Wednesday, December 22, 2004 5:04 PM To: pgsql-general@postgresql.org Subject: [GENERAL] migrating from mysql Hi everyone, I am new to postgresql. I am planning to migrate our current database (mysql) to posgresql. I am currently having difficulties dealing with the order of the tables that is created. Here is what I do: 1. I use myqsldump to get the schema and data. 2. I use my2pg and a java utility I created to convert mysqldump to sql statement that is understood by postgresql. 3. When populating the data to postgresql, it complained relation "xxx" doesn't exist. This is the case because the table that is refrenced has not been created. The quick fix to this will be to change the sequence of the tables that are created in such a way that tables that are being referenced are first created before referencing table. However, this is not practical if we have many tables. My questions is: is there a way to get around this? is it possible to disable checking for relation when creating a table that is referencing to other tables? I've searched around the internet and found somebody mentioning about disable-fk-verifications, but I got an error (something like invalid configuration parameters). I am currently using postgresql 7.4.6. Any ideas/suggestions is greatly appreciated. J ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org