1. Lock the table against all reads and writes. 2. Create a new table with a fabricated name, and with all the schema changes in place. Note: if you are making multiple changes, do them in a single ALTER. 3. Do (effectively) "INSERT INTO new SELECT ... FROM old" -- This is ...
Beyond that, BigQuery does not allow many other changes, such as column removal or renaming (though these can be performed indirectly by copying the columns you wish to retain to a new table, destroying the original, then creating a replacement table with the new data). For the time being ...
So, even if none of the existing columns of your problematictable is unique, it is still to add another unique column to act as the primary key. The internal GEN_CLUST_INDEX one is not exposed to the upper MySQL layer, and only theInnoDB engine is aware of it, hence it is useless...
nice workarounds described here: Storing UUID Values in MySQL UUIDs are Popular, but Bad for Performance— Let’s Discuss Storing UUID and Generated Columns And cut the UUID overhead significantly I encourage you to check more details on good practices for choosing the primary key in ...
The table name defaults totable1. Change the name by enteringinvoiceinto theName:field. Changes here affect the name of the tab in the table editor and the name of the table on the canvas. PressingTaborEnterwhile the cursor is in the table name field selects theColumnstab of the table ...
You can do this by issuing, for each NDBCLUSTER table, an OPTIMIZE TABLE statement in the mysql client. This works for space used by variable-width columns of in-memory NDB tables. OPTIMIZE TABLE is not supported for fixed-width columns of in-memory tables; it is also not supported for...
But if that’s not an option (say your client’s support contract only covers MySQL), there’s still a way to write your migrations such that Postgres, SQLite, and MySQL all behave in the same correct way when adding NOT NULL columns to existing tables: add the column first, then add...
Category:MySQL WorkbenchSeverity:S3 (Non-critical) Version:5.0.30OS:Windows (Vista) Assigned to:CPU Architecture:Any Tags:5.0.30,add column,exception,workbench [24 Jun 2009 18:33] Paul Warren Description:A reproducible unhandled exception in MySQL Workbench. The error I get is below, See the ...
Postgres got support for the INCLUDE clause in CREATE INDEX. This can be used to add non-key columns to the index. CREATE INDEX idx ON t1 ( col1 ) INCLUDE ( col2 ); This allows for Index Only Scans on queries like: SELECT col1, col2 FROM t1 WHERE t1 = 'foo'; More info...
Alter table structure conditional adding columns if they dont already existPosted by: Frank Thomson Date: October 10, 2007 03:43PM A bit of background first. I have a laptop that I use for development. This has php, mysql and apache installed and working. I have a separate production ...