Category Archives: Constraints

Adding a Column with a Default Value and a Constraint

Oren Nakdimon Leave a Reply

The Constraint Optimization series: Part 1: Optimization of Check Constraint Creation Part 2: Optimization that Violates Data Integrity Part 3: Optimization of Foreign Key Constraint Creation Part 4: (Lack of) Optimization of Unique Constraint Creation Part 5: Adding a Column with a Default Value and a Constraint In the previous parts of this series I […]

Continue reading

(Lack of) Optimization of Unique Constraint Creation

Oren Nakdimon 1 Reply

The Constraint Optimization series: Part 1: Optimization of Check Constraint Creation Part 2: Optimization that Violates Data Integrity Part 3: Optimization of Foreign Key Constraint Creation Part 4: (Lack of) Optimization of Unique Constraint Creation Part 5: Adding a Column with a Default Value and a Constraint In the previous parts of this series I […]

Continue reading

Optimization of Foreign Key Constraint Creation

Oren Nakdimon Leave a Reply

The Constraint Optimization series: Part 1: Optimization of Check Constraint Creation Part 2: Optimization that Violates Data Integrity Part 3: Optimization of Foreign Key Constraint Creation Part 4: (Lack of) Optimization of Unique Constraint Creation Part 5: Adding a Column with a Default Value and a Constraint In a recent post I showed that Oracle […]

Continue reading

Optimization that Violates Data Integrity

Oren Nakdimon 1 Reply

The Constraint Optimization series: Part 1: Optimization of Check Constraint Creation Part 2: Optimization that Violates Data Integrity Part 3: Optimization of Foreign Key Constraint Creation Part 4: (Lack of) Optimization of Unique Constraint Creation Part 5: Adding a Column with a Default Value and a Constraint In the previous post I showed that Oracle […]

Continue reading

Optimization of Check Constraint Creation

Oren Nakdimon 3 Replies

The Constraint Optimization series: Part 1: Optimization of Check Constraint Creation Part 2: Optimization that Violates Data Integrity Part 3: Optimization of Foreign Key Constraint Creation Part 4: (Lack of) Optimization of Unique Constraint Creation Part 5: Adding a Column with a Default Value and a Constraint I have a table T with many records […]

Continue reading

A Recipe for Summoning the RBO Monster (even in Oracle 12c): On Delete Cascade, Function-Based Index and Missing Table Statistics

Oren Nakdimon Leave a Reply

The last version of Oracle in which CHOOSE was officially supported as an OPTIMIZER_MODE parameter value was 9.2. This is what the documentation of Oracle 9.2 says about it: choose The optimizer chooses between a cost-based approach and a rule-based approach based on whether statistics are available. If the data dictionary contains statistics for at […]

Continue reading

impdp – which rows failed?

Oren Nakdimon 2 Replies

Since version 11.1, Data Pump Import supports the SKIP_CONSTRAINT_ERRORS option, which specifies that you want the import operation to proceed even if (non-deferred) constraint violations are encountered. It logs any rows that cause constraint violations, but does not stop, and does load the other rows. If SKIP_CONSTRAINT_ERRORS is not set, then the default behavior is […]

Continue reading