Online Database Object Changes

Michael J Swart continues his online deployment series:

PROCEDURES:
Procedures are very easy to Blue-Green. Brand new procedures are added during the pre-migration phase. Obsolete procedures are dropped during the post-migration phase.

If the procedure is changing but is logically the same, then it can be altered during the pre-migration phase. This is common when the only change to a procedure is a performance improvement.

But if the procedure is changing in other ways. For instance, when a new parameter is added, or dropped, or the resultset is changing. Then use the Blue-Green method to replace it: During the pre-migration phase, create a new version of the procedure. It must be named differently and the green version of the application has to be updated to call the new procedure. The original blue version of the procedure is deleted during the post-migration phase. It’s not always elegant calling a procedure something like s_USERS_Create_v2 but it works.

This has been a great series so far, and the way he does deployments matches very closely to the way we do them.

Related Posts

The Stage-And-Switch Technique For Deployments

Michael Swart amps up the complexity factor in his online deployment series: There’s two things going on here (and one hidden thing): The first two messages point out that a procedure is referencing the column ColdRoomSensorNumber with schemabinding. The reason it’s using schemabinding is because it’s a natively compiled stored procedure. And that tells me that the table Warehouse.ColdRoomTemperatures is […]

Read More

OLTP-Friendly Database Deployments

Michael Swart looks at one of the biggest problems when trying to do a zero-downtime deployment to an OLTP system: There are two main kinds of SQL queries. SELECT/INSERT/UPDATE/DELETE statements are examples of Data Manipulation Language (DML). CREATE/ALTER/DROP statements are examples of Data Definition Language (DDL). With schema changes – DDL – we have the […]

Read More

Leave a Reply

Your email address will not be published. Required fields are marked *

Categories

January 2018
MTWTFSS
« Dec  
1234567
891011121314
15161718192021
22232425262728
293031