Sybase Adaptive Server IQ 12.4.2 Administration And Performance Manual page 10

Contents
CHAPTER 8
CHAPTER 9
x
Referential integrity is unenforced......................................... 284
Integrity rules in the system tables ............................................... 285
Transactions and Versioning ..................................................... 287
Overview of transactions and versioning ..................................... 287
Introduction to transactions ................................................... 287
Introduction to concurrency ................................................... 290
Introduction to versioning ...................................................... 291
Versioning prevents inconsistencies ............................................ 299
How locking works ....................................................................... 299
Locks for DML operations ..................................................... 299
Locks for DDL operations...................................................... 300
Primary keys and locking ...................................................... 302
Isolation levels.............................................................................. 302
Checkpoints, savepoints, and transaction rollback ...................... 303
Checkpoints........................................................................... 304
Savepoints within transactions .............................................. 305
Rolling back transactions ...................................................... 307
System recovery.................................................................... 307
How transaction information aids recovery ........................... 308
Performance implications ............................................................. 309
Overlapping versions and deletions ...................................... 310
Cursors in transactions ................................................................ 311
Cursors and versioning ......................................................... 312
Cursor sensitivity ................................................................... 312
Cursor scrolling ..................................................................... 312
Hold cursors .......................................................................... 313
Positioned operations............................................................ 313
Cursor command syntax and examples ................................ 313
Controlling message logging for cursors ............................... 313
International Languages and Character Sets ........................... 315
Introduction to international languages and character sets.......... 315
Adaptive Server IQ international features ............................. 315
Using the default collation ..................................................... 316
Character set questions and answers ................................... 316
Understanding character sets in software.................................... 317
Pieces in the character set puzzle......................................... 317
Language issues in client/server computing ......................... 318
Code pages in Windows and Windows NT ........................... 319
Multibyte character sets ........................................................ 321
Sorting characters using collations........................................ 322
International aspects of case sensitivity ................................ 322