1. Dynamic SQL
Konstantin Osipov, MySQL AB

2. About the speaker lives in Moscow works on the server
implemented the feature

3. What is this talk about? how Dynamic SQL works good practices
getting your feedback

4. Dynamic SQL syntax is syntax of SQL prepared statements:
PREPARE <name> FROM <text>
EXECUTE <name> USING list>
DEALLOCATE PREPARE <name>

5. Degree of Freedom Static SQL: @-user variables to input data
Stored Procedures SQL: stored procedure variables
Prepared SQL: adds LIMIT ?, ? capability
Dynamic SQL: 100% flexibility

6. Permissions, Scope
Permissions: are the same as of the Stored Procedure
dangerous in SUID procedures
Scope: Dynamic SQL has its own scope
no access to SP variables
temporary tables are in the scope of SP

7. How it works

8. Dynamic SQL Dos administrative tasks CHECK, OPTIMIZE dynamic querying
IN (id-list), handling of hierarchical data

9. Dynamic SQL Dont's
don't use it if you don't have to: risk of SQL injection
it does not provide extra optimization
Static SQL is re-optimized just as well
it allows the same statements as in Stored Procedures

10. Dynamic SQL Limits not all statements
three step procedure: no EXECUTE IMMEDIATE
no cursor support
no access to Stored Procedure variables
Stored Procedure variables can't be bound to placeholders
can't be used in Functions and Triggers

11. Questions?