"SHOW TABLE STATUS very slow w/large number of tables"
Replaced old algorithm which were used in my_dir() and stored
all information about directory entries in one chunk of memory
with new one which stores file names and MY_STAT structures in
separate memroot, so now we don't need to copy this data during
reallocation of dir_entry array.
include/my_dir.h:
Changed mystat member of FILEINFO structure to pointer since
this prevents unneeded memory allocation and initialization.
Added comment about new hidden members of MY_DIR structure.
mysys/my_lib.c:
Replaced old algorithm in my_dir() which stored all information
about directory entries in one chunk of memory with new one
which stores file names and MY_STAT structures in separate
memroot. Now we don't copy this data during reallocation of
array with FILEINFO structures.
Also tuned sizes of memory chunks during first-other
reallocations (we suppose that we either have < 100 files
in the directory or > 1000 of them).
sql/sql_show.cc:
Updated only place in code where mystat member
of FILEINFO structure is used.
c545b02645