NAME
SQLITE_SCANSTAT_NLOOP,
SQLITE_SCANSTAT_NVISIT,
SQLITE_SCANSTAT_EST,
SQLITE_SCANSTAT_NAME,
SQLITE_SCANSTAT_EXPLAIN,
SQLITE_SCANSTAT_SELECTID —
Prepared
Statement Scan Status Opcodes
SYNOPSIS
#define SQLITE_SCANSTAT_NLOOP
#define SQLITE_SCANSTAT_NVISIT
#define SQLITE_SCANSTAT_EST
#define SQLITE_SCANSTAT_NAME
#define SQLITE_SCANSTAT_EXPLAIN
#define SQLITE_SCANSTAT_SELECTID
DESCRIPTION
The following constants can be used for the T parameter to the
sqlite3_stmt_scanstatus(S,X,T,V) interface. Each constant designates a
different metric for sqlite3_stmt_scanstatus() to return.
When the value returned to V is a string, space to hold that string is managed
by the prepared statement S and will be automatically freed when S is
finalized.
-
-
- SQLITE_SCANSTAT_NLOOP
- The sqlite3_int64 variable pointed to by the T parameter
will be set to the total number of times that the X-th loop has run.
-
-
- SQLITE_SCANSTAT_NVISIT
- The sqlite3_int64 variable pointed to by the T parameter
will be set to the total number of rows examined by all iterations of the
X-th loop.
-
-
- SQLITE_SCANSTAT_EST
- The "double" variable pointed to by the T
parameter will be set to the query planner's estimate for the average
number of rows output from each iteration of the X-th loop. If the query
planner's estimates was accurate, then this value will approximate the
quotient NVISIT/NLOOP and the product of this value for all prior loops
with the same SELECTID will be the NLOOP value for the current loop.
-
-
- SQLITE_SCANSTAT_NAME
- The "const char *" variable pointed to by the T
parameter will be set to a zero-terminated UTF-8 string containing the
name of the index or table used for the X-th loop.
-
-
- SQLITE_SCANSTAT_EXPLAIN
- The "const char *" variable pointed to by the T
parameter will be set to a zero-terminated UTF-8 string containing the
EXPLAIN QUERY PLAN description for the X-th loop.
-
-
- SQLITE_SCANSTAT_SELECT
- The "int" variable pointed to by the T parameter
will be set to the "select-id" for the X-th loop. The select-id
identifies which query or subquery the loop is part of. The main query has
a select-id of zero. The select-id is the same value as is output in the
first column of an EXPLAIN QUERY PLAN query.
SEE ALSO
sqlite_int64(3)