. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 8.4.4. NULL status bitmap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0x02 The Page Inventory Page (PIP). This page keeps track of allocated and free pages using a bitmap where a 1 means the page is free, and a 0 (zero) shows a used page. There may be more than one PIP keeps track of the stat of transactions. Each transaction is represented by a pair of bits in a bitmap. Valid values in these two bits are: 00 this transaction is active. 01 this transaction is in

EXPLAIN форме: Select Expression -> Filter -> Table "STUDENTS" Access By ID -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (full match) -> Table "STUDENTS" Access By ID -> Index "PK_STUDENTS" Full Scan -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) "STUDENTS" Access By ID -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1)

(DML) Statements 289 Select Expression -> Filter -> Table "STUDENTS" Access By ID -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (full match) The INDEX directive is also used for join -> Filter -> Table "STUDENTS" Access By ID -> Index "PK_STUDENTS" Full Scan -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) It is perfectly OK if ORDER and Table "STUDENTS" Access By ID -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) For sorting sets when there’s no

(ix_stud_class)); Erweiterter Plan: Select Expression -> Filter -> Table "STUDENTS" Access By ID -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (full match) Die Direktive INDEX wird auch für Join-Bedingungen -> Filter -> Table "STUDENTS" Access By ID -> Index "PK_STUDENTS" Full Scan -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) Es ist vollkommen in Ordnung, wenn Table "STUDENTS" Access By ID -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) -> Bitmap -> Index "IX_STUD_CLASS" Range Scan (lower bound: 1/1) Um Sets zu sortieren, wenn kein

emp_no = 107; Select Expression -> Filter -> Table "EMPLOYEE" Access By ID -> Bitmap -> Index "RDB$PRIMARY7" Unique Scan EMP_NO FIRST_NAME LAST_NAME ======= ===============

rollback Identification of the exact RDB$TRIGGER_TYPE code is a little more complicated, since it is a bitmap, calculated according to which phase and events are covered and the order in which they are defined