Quiz library

If a session makes a change to a table on which a cache is reliant, but that session does not commit those changes, then the cache is disabled for the current session only. Data recovery best The cache is still valid for and used by all other sessions.Author: Steven Feuerstein [1277-2032622]

When you fetch from a cursor whose SELECT contains a cursor expression, you do not have to open the cursor; that will be done when you fetch the row. Data recovery program In addition, cursor variables to which the expressions are assigned will be automatically closed when the cursor they were fetched from is closed.Author: Steven Feuerstein [21786-2032621]

If a parameter or variable could be NULL, then examine your conditional logic carefully to ensure that this (non) value is handled properly.Author: Steven Feuerstein [8829-2020581]

Whenever you find yourself looping through the contents of an collection searching for a match, consider: creating a second collection that serves as an index into the array; using MEMBER OF with nested tables if appropriate.Author: Steven Feuerstein [21686-2020561]

When referencing collection elements in static DML, use as simple expression as possible in order to avoid unexpected errors. For example, you cannot use local functions or collection methods of a non-SQL collection as part of an expression that evaluates to the index of collection element.Author: Elic (50612) [10662-1979222]

Starting with Oracle Database 12c Release 1, you can use the TABLE operator with associative arrays that are indexed by integer.Author: Steven Feuerstein [20786-1992801]

When working with true-false (Boolean) logic in PL/SQL code, use the BOOLEAN datatype, rather than strings or numbers (which you still have to do with column values in tables).

7 data recovery 94fbr Native Boolean logic is more expressive and easier to maintain.Author: Steven Feuerstein [20526-1978921]

If your conditional logic consists simply of IF-ELSE or even more simply IF (no ELSE clause), then you should an IF statement and not a CASE statement. Database languages CASE statements are best used in place of IF-ELSIF-ELSIF… Database ranking constructs.Author: Steven Feuerstein [7250-1979221]

When you use RPAD and LPAD, you specify the length to which you want to pad, not the number of characters of padding you desire.Author: Steven Feuerstein [20586-1982021]

After executing an implicit cursor in PL/SQL (a SELECT-INTO and any DML statement – insert, update, delete, merge), SQL%ISOPEN always returns FALSE and SQL%FOUND returns TRUE. Data recovery youtube SQL%ROWCOUNT returns the number of rows modified or fetched by the cursor.Author: Steven Feuerstein [6207-1963845]

When you call SQLCODE outside of an exception section, it always returns 0. 911 database Which means no error. Data recovery download Which makes sense, right? You’re not in an exception section, so there’s no error.Author: Steven Feuerstein [20366-1963846]

You can use savepoints to constrain the impact of a rollback, preserving all changes in your sessions up to that save point. Data recovery after factory reset But if you are looking into this functionality, also consider using the AUTONOMOUS_TRANSACTION pragma.Author: Steven Feuerstein [20346-1963844]

If a SELECT-INTO finds no rows, Oracle raises NO_DATA_FOUND. Database schema design If, on the other hand, a DELETE or UPDATE find/change no rows, no exception is raised.Author: Steven Feuerstein [20128-1940208]

Be very, very wary of CHAR variables and constants in your code. Database uml They can cause all sorts of hard-to-debug problems. Data recovery ntfs In fact, why use CHAR at all? Always use VARCHAR2!Author: Steven Feuerstein [20126-1940205]

If you need to continue past errors from DML operations, you can define a nested block to narrow propagation of the exception, or SAVE EXCEPTIONS with FORALL, or LOG ERRORS (after you’ve created an error logging table). Database error Each approach has different strengths and weaknesses.Author: Steven Feuerstein [7719-1940210]