Improvements to the description of the OPFLAG_TYPEOFARG option to OP_Column.

FossilOrigin-Name: 5e9c67ba18b701aabbb0546acdfc532c9e8f0d27fb0a2c899415a5c47096c90b

1 files changed, 6 insertions, 4 deletions

diff --git a/src/vdbe.c b/src/vdbe.c
index b4a96468f..f8878db31 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2781,10 +2781,12 @@ case OP_Offset: {          /* out3 */
 ** if the P4 argument is a P4_MEM use the value of the P4 argument as
 ** the result.
 **
-** If the OPFLAG_LENGTHARG and OPFLAG_TYPEOFARG bits are set on P5 then
-** the result is guaranteed to only be used as the argument of a length()
-** or typeof() function, respectively.  The loading of large blobs can be
-** skipped for length() and all content loading can be skipped for typeof().
+** If the OPFLAG_LENGTHARG bit is set in P5 then the result is guaranteed
+** to only be used by the length() function or the equivalent.  The content
+** of large blobs is not loaded, thus saving CPU cycles.  If the
+** OPFLAG_TYPEOFARG bit is set then the result will only be used by the
+** typeof() function or the IS NULL or IS NOT NULL operators or the
+** equivalent.  In this case, all content loading can be omitted.
 */
 case OP_Column: {
   u32 p2;            /* column number to retrieve */