>= '2008-01-01' ::date) Some or all of the partitions might use index scans instead of full-table sequential scans, but the point here is that there is no need to scan the older partitions at all index scans. The system can form AND and OR conditions across several index scans. For example, a query like WHERE x = 42 OR x = 47 OR x = 53 OR x = 99 could be broken down into four separate scans of an an index on x, each scan using one of the query clauses. The results of these scans are then ORed together to produce the result. Another example is that if we have separate indexes on x and y, one possible

Operator Classes and Operator Families ...395 11.10. Indexes and Collations ...397 11.11. Index-Only Scans ...397 11.12. Examining Index Usage ...399 12. Full Text Search ...401 12.1. Introduction 479 15.2. When Can Parallel Query Be Used? ... 480 15.3. Parallel Plans ... 481 15.3.1. Parallel Scans ... 481 15.3.2. Parallel Joins ... 481 15.3.3. Parallel Aggregation ... 481 15.3.4. Parallel Plan Custom Scan Plans ...2255 57.2.1. Custom Scan Plan Callbacks ...2256 57.3. Executing Custom Scans ...2256 57.3.1. Custom Scan Execution Callbacks ...2257 58. Genetic Query Optimizer ...2259

.... 384 11.7. Indexes on Expressions ..... 385 11.8. Partial Indexes ..... 385 11.9. Index-Only Scans and Covering Indexes ..... 388 11.10. Operator Classes and Operator Families ..... 391 11 Custom Scan Paths ..... 2201 59.2. Creating Custom Scan Plans ..... 2202 59.3. Executing Custom Scans ..... 2203 60. Genetic Query Optimizer ..... 2206 60.1. Query Handling as a Complex Optimization .... 384 11.7. Indexes on Expressions ..... 385 11.8. Partial Indexes ..... 385 11.9. Index-Only Scans and Covering Indexes ..... 388 11.10. Operator Classes and Operator Families ..... 391 11

................................................................................. 405 11.9. Index-Only Scans and Covering Indexes ...................................................... 408 11.10. Operator .................................................................... 2325 59.3. Executing Custom Scans ......................................................................... 2326 60. Genetic Query Optimizer ................................................................................. 405 11.9. Index-Only Scans and Covering Indexes .............................................................. 408 11.10

.... 430 11.7. Indexes on Expressions ..... 430 11.8. Partial Indexes ..... 431 11.9. Index-Only Scans and Covering Indexes ..... 434 11.10. Operator Classes and Operator Families ..... 437 11 Custom Scan Paths ..... 2377 58.2. Creating Custom Scan Plans ..... 2378 58.3. Executing Custom Scans ..... 2379 59. Genetic Query Optimizer ..... 2382 59.1. Query Handling as a Complex Optimization Indexes ..... 430 11.7. Indexes on Expressions ..... 430 11.8. Partial Indexes ..... 431 11.9. Index-Only Scans and Covering Indexes ..... 434 11.10. Operator Classes and Operator Families ..... 437 11

.... 426 11.7. Indexes on Expressions ..... 426 11.8. Partial Indexes ..... 427 11.9. Index-Only Scans and Covering Indexes ..... 430 11.10. Operator Classes and Operator Families ..... 433 11 Custom Scan Paths ..... 2379 58.2. Creating Custom Scan Plans ..... 2380 58.3. Executing Custom Scans ..... 2381 59. Genetic Query Optimizer ..... 2384 59.1. Query Handling as a Complex Optimization Indexes ..... 426 11.7. Indexes on Expressions ..... 426 11.8. Partial Indexes ..... 427 11.9. Index-Only Scans and Covering Indexes ..... 430 11.10. Operator Classes and Operator Families ..... 433 11

.... 403 11.7. Indexes on Expressions ..... 404 11.8. Partial Indexes ..... 404 11.9. Index-Only Scans and Covering Indexes ..... 407 11.10. Operator Classes and Operator Families ..... 410 11 Custom Scan Paths ..... 2249 58.2. Creating Custom Scan Plans ..... 2250 58.3. Executing Custom Scans ..... 2251 59. Genetic Query Optimizer ..... 2254 59.1. Query Handling as a Complex Optimization .... 403 11.7. Indexes on Expressions ..... 404 11.8. Partial Indexes ..... 404 11.9. Index-Only Scans and Covering Indexes ..... 407 11.10. Operator Classes and Operator Families ..... 410 11

.... 406 11.7. Indexes on Expressions ..... 407 11.8. Partial Indexes ..... 407 11.9. Index-Only Scans and Covering Indexes ..... 410 11.10. Operator Classes and Operator Families ..... 413 11 Custom Scan Paths ..... 2244 58.2. Creating Custom Scan Plans ..... 2245 58.3. Executing Custom Scans ..... 2246 59. Genetic Query Optimizer ..... 2249 59.1. Query Handling as a Complex Optimization .... 406 11.7. Indexes on Expressions ..... 407 11.8. Partial Indexes ..... 407 11.9. Index-Only Scans and Covering Indexes ..... 410 11.10. Operator Classes and Operator Families ..... 413 11

Operator Classes and Operator Families ..... 385 11.10. Indexes and Collations ..... 387 11.11. Index-Only Scans ..... 387 11.12. Examining Index Usage ..... 389 12. Full Text Search ..... 391 12.1. Custom Scan Paths ..... 2184 58.2. Creating Custom Scan Plans ..... 2185 58.3. Executing Custom Scans ..... 2186 59. Genetic Query Optimizer ..... 2189 59.1. Query Handling as a Complex Optimization Operator Classes and Operator Families ..... 385 11.10. Indexes and Collations ..... 387 11.11. Index-Only Scans ..... 387 11.12. Examining Index Usage ..... 389 12. Full Text Search ..... 391 12.1.

Operator Classes and Operator Families ..... 366 11.10. Indexes and Collations ..... 367 11.11. Index-Only Scans ..... 367 11.12. Examining Index Usage ..... 369 12. Full Text Search ..... 371 12.1. Custom Scan Paths ..... 2079 58.2. Creating Custom Scan Plans ..... 2080 58.3. Executing Custom Scans ..... 2081 59. Genetic Query Optimizer ..... 2083 59.1. Query Handling as a Complex Optimization Operator Classes and Operator Families ..... 366 11.10. Indexes and Collations ..... 367 11.11. Index-Only Scans ..... 367 11.12. Examining Index Usage ..... 369 12. Full Text Search ..... 371 12.1.