The PL/Scope Resource Center
The PL/Scope Resource Center
Let's look at PL/Scope and its answers to several questions about code being at risk, constants, variables, and exceptions.
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PL/Scope is a compiler-driven tool that collects PL/SQL and SQL identifiers as well as SQL statements usage in PL/SQL source code. PL/Scope collects PL/SQL identifiers, SQL identifiers, and SQL statements metadata at program-unit compilation time and makes it available in static data dictionary views. The collected data includes information about identifier types, usages (DECLARATION, DEFINITION, REFERENCE, CALL, ASSIGNMENT), and the location of each usage in the source code.
Starting with Oracle Database 12cRelease 2 (12.2), PL/Scope has been enhanced to report on the occurrences of static SQL and dynamic SQL call sites in PL/SQL units. The call site of the native dynamic SQL (EXECUTE IMMEDIATE, OPEN CURSOR FOR) and DBMS_SQL calls are collected. Dynamic SQL statements are generated at execution time, so only the call sites can be collected at compilation time. The collected data in the new DBA_STATEMENTS view can be queried along with the other data dictionary views to help answer questions about the scope of changes required for programming projects, and performing code analysis. It is also useful to identify the source of SQL statement not performing well.
PL/Scope provides insight into dependencies between tables, views, and the PL/SQL units. This level of detail can be used as a migration assessment tool to determine the extent of changes required.
PL/Scope can help you answer questions such as:
- Where and how a column x in table y is used in the PL/SQL code.
- Where does the same SQL statement appear more than once in my code?
- What are the constants, variables, and exceptions in my application that are declared but never used?
- Is my code at risk for SQL injection?
- What are the SQL statements with an optimizer hint coded in the application?
- Where is a variable modified in my package?
I've collected below a set of resources to help you make the most of PL/Scope.
The documentation contains key information you'll need to turn on the gathering of identifier data and write your own queries against the PL/Scope data dictionary views.
LiveSQL Scripts on PL/Scope
LiveSQL offers 24x7 access to the most recent release of Oracle Database. You can write your own scripts, play around with SQL and PL/SQL, and take advantage of a code library of scripts submitted by Oracle experts and the community. I've uploaded a whole bunch of scripts showcasing the capabilities of PL/Scope.
Philipp offers a fantastic set of utilities to help you make the most of PL/Scope. His description:
PL/Scope was introduced with Oracle Database version 11.1 and covered PL/SQL only. SQL statements such as SELECT, INSERT, UPDATE, DELETE and MERGE were simply ignored. Analysing PL/SQL source code without covering SQL does not provide a lot of value. Hence, PL/Scope was neglected by the Oracle community. But this seems to change with version 12.2. PL/Scope covers SQL statements, finally. This makes fine-grained dependency analysis possible. Fine-grained means on column level and on package unit level (procedure/function).
PL/Scope is something like a software development kit (SDK) for source code analysis. It consists basically of the following two components:
- The compiler, which collects information when compiling source code (e.g. plscope_settings='identifiers:all')
- The dictionary views, providing information about collected identifiers (dba_identifiers) and SQL statements (dba_statements).
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