Database Concurrency Control
{"Image DocumentName": "Database Concurrency Control", "Image ImageDescription": "Two-Phase Locking Techniques: The algorithm. T1 T2 Result. read_lock (Y); read_lock (X); Initial values: X=20; Y=30. read_item (Y); read_item (X); Result of serial execution. unlock (Y); unlock (X); T1 followed by T2. write_lock (X); Write_lock (Y); X=50, Y=80. read_item (X); read_item (Y); Result of serial execution. X:=X+Y; Y:=X+Y; T2 followed by T1. write_item (X); write_item (Y); X=70, Y=50. unlock (X); unlock (Y);", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}