.Dd December 19, 2018
.Dt SQLITE_SCANSTAT_NLOOP 3
.Os
.Sh NAME
.Nm SQLITE_SCANSTAT_NLOOP ,
.Nm SQLITE_SCANSTAT_NVISIT ,
.Nm SQLITE_SCANSTAT_EST ,
.Nm SQLITE_SCANSTAT_NAME ,
.Nm SQLITE_SCANSTAT_EXPLAIN ,
.Nm SQLITE_SCANSTAT_SELECTID
.Nd Prepared Statement Scan Status Opcodes
.Sh SYNOPSIS
.Fd #define SQLITE_SCANSTAT_NLOOP
.Fd #define SQLITE_SCANSTAT_NVISIT
.Fd #define SQLITE_SCANSTAT_EST
.Fd #define SQLITE_SCANSTAT_NAME
.Fd #define SQLITE_SCANSTAT_EXPLAIN
.Fd #define SQLITE_SCANSTAT_SELECTID
.Sh 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.
.Pp
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.
.Bl -tag -width Ds
.It 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.
.It 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.
.It 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.
.It 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.
.It 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.
.It 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.
.El
.Pp
.Sh SEE ALSO
.Xr sqlite_int64 3