Replace ut_ad(mtr_memo_contains(mtr, buf_block_align(ptr), ...))
with ut_ad(mtr_memo_contains_page(mtr, ptr, ...)) in order to reduce the
number of buf_block_align() calls.
in the clustered index to be smaller than the indexed prefix in secondary
indexes.
row_ext_lookup(): Return NULL if the column is not stored externally.
trx_undo_rec_get_partial_row(): row_build(): Add parameter row_ext_t** ext.
row_build_index_entry(): Add the parameter row_ext_t* ext.
Invoke row_ext_lookup() to fetch prefixes of externally stored columns.
upd_node_t, undo_node_t, purge_node_t: Add the field row_ext_t* ext.
of clustered indexes. Previously, parts of the code assumed that these
columns would exist on all leaf pages. Simplify the update-in-place of
these columns.
Add inline function dict_index_is_clust() to replace all tests
index->type & DICT_CLUSTERED.
Remove the redo log entry types MLOG_ZIP_WRITE_TRX_ID and
MLOG_ZIP_WRITE_ROLL_PTR, because the modifications to these columns
are covered by logical logging.
Fuse page_zip_write_trx_id() and page_zip_write_roll_ptr() into
page_zip_write_trx_id_and_roll_ptr().
page_zip_dir_add_slot(), page_zip_available(): Add flag "is_clustered",
so that no space will be reserved for TRX_ID and ROLL_PTR on leaf pages
of secondary indexes.
page_zip_apply_log(): Flag an error when val==0 is encoded with two bytes.
page_zip_write_rec(): Add debug assertions that there is enough space
available for the entry before copying the data bytes of the record.
