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<< SYSXPLAIN_SCAN_PROPS system table | SCAN_QUALIFIERS >>

NO_QUALIFIED_ROWS

<< SYSXPLAIN_SCAN_PROPS system table | SCAN_QUALIFIERS >>
Derby Reference Manual
253
Column Name
Type
Length
Nullable
Contents
SCAN_TYPE
CHAR
8
false
The type of scan
being performed. Scan
types include 'HEAP',
'BTREE', and 'SORT'.
ISOLATION_LEVEL
CHAR
3
true
The isolation level
being used for this
scan. Isolation levels
are identified by a
code: 'RU' for Read
Uncommitted, 'RC'
for Read Committed,
'RR' for Repeatable
Read, and 'SE' for
Serializable.
NO_VISITED_PAGES
INTEGER
10
true
Number of database
pages that this scan
touched. For btree
scans this number only
includes the leaf pages
visited.
NO_VISITED_ROWS
INTEGER
10
true
Number of database
rows that were
examined by this scan.
This number includes
all rows, including those
rows marked deleted,
those rows that don't
meet qualification, and
those rows which were
returned by the scan.
NO_QUALIFIED_ROWS
INTEGER
10
true
Number of rows that
satisfied the qualifiers
for this scan.
NO_VISITED_DELETED_ROWS
INTEGER
10
true
Number of the
database rows that
were examined by this
scan which were found
to be rows that were
marked deleted.
NO_FETCHED_COLUMNSINTEGER
10
true
Number of columns that
were fetched from each
qualifying row.
BITSET_OF_FETCHED_COLUMNS
VARCHAR
32,672
true
Description of the
columns which were
fetched from each
qualifying row.
BTREE_HEIGHT
INTEGER
10
true
For a scan of type
BTREE, this column
holds the height of
the BTREE index.