Small. Fast. Reliable.
Choose any three.
#define SQLITE_SCANSTAT_NLOOP 0
#define SQLITE_SCANSTAT_NVISIT 1
#define SQLITE_SCANSTAT_EST 2
#define SQLITE_SCANSTAT_NAME 3
#define SQLITE_SCANSTAT_EXPLAIN 4
#define SQLITE_SCANSTAT_SELECTID 5
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
-
R-52416-32346:[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
-
R-45249-57463:[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
-
R-30129-51241:[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
-
R-43811-17362:[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
-
R-16489-33536:[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
-
R-22825-10487:[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 lists of
Objects,
Constants, and
Functions.