Description:
The internal SDI index's table description is created in-memory as (type, id, compressed_len, uncompressed_len, data), however it's read and written to as (type, id, uncompressed_len, compressed_len, data). That is, the order of the compressed_len and uncompressed_len fields is reversed compared to the definition.
Since all access to this index is positional as columns 2 and 3 as far as I could find, and the field types are the same, this doesn't end up mattering in actual usage. However, in memory in the index definition, the column names are incorrect, and this should be fixed to avoid future confusion or mishaps.
Index creation/definition occurs in storage/innobase/dict/dict0crea.cc:
651 dict_index_t *dict_sdi_create_idx_in_mem(space_id_t space, bool space_discarded,
652 uint32_t in_flags, bool is_create) {
...
692 dict_mem_table_add_col(table, heap, "type", DATA_INT,
693 DATA_NOT_NULL | DATA_UNSIGNED, 4, true);
694 dict_mem_table_add_col(table, heap, "id", DATA_INT,
695 DATA_NOT_NULL | DATA_UNSIGNED, 8, true);
696 dict_mem_table_add_col(table, heap, "compressed_len", DATA_INT,
697 DATA_NOT_NULL | DATA_UNSIGNED, 4, true);
698 dict_mem_table_add_col(table, heap, "uncompressed_len", DATA_INT,
699 DATA_NOT_NULL | DATA_UNSIGNED, 4, true);
700 dict_mem_table_add_col(table, heap, "data", DATA_BLOB, DATA_NOT_NULL, 0,
701 true);
Reading and writing occurs in storage/innobase/api/api0api.cc:
2716 static ib_tpl_t ib_sdi_create_insert_tuple(ib_crsr_t ib_crsr,
2717 const sdi_key_t *sdi_key,
2718 uint32_t uncomp_len,
2719 uint32_t comp_len, const void *sdi) {
...
2723 ib_tpl_t tuple = ib_clust_read_tuple_create(ib_crsr);
2724 ib_col_set_value(tuple, 0, &sdi_key->type, SDI_TYPE_LEN, false);
2725 ib_col_set_value(tuple, 1, &sdi_key->id, SDI_KEY_LEN, false);
2726 ib_col_set_value(tuple, 2, &uncomp_len, 4, false);
2727 ib_col_set_value(tuple, 3, &comp_len, 4, false);
2728 ib_col_set_value(tuple, 4, sdi, comp_len, false);
and
2935 dberr_t ib_sdi_get(uint32_t tablespace_id, const ib_sdi_key_t *ib_sdi_key,
2936 void *comp_sdi, uint32_t *comp_sdi_len,
2937 uint32_t *uncomp_sdi_len, trx_t *trx) {
...
2975 ib_tuple_read_u32(tuple, 2, uncomp_sdi_len);
2976 ib_tuple_read_u32(tuple, 3, comp_sdi_len);
How to repeat:
Examine the code.
Suggested fix:
Reverse the order of the compressed_len and uncompressed_len fields in dict_sdi_create_idx_in_mem() in storage/innobase/dict/dict0crea.cc.
Description: The internal SDI index's table description is created in-memory as (type, id, compressed_len, uncompressed_len, data), however it's read and written to as (type, id, uncompressed_len, compressed_len, data). That is, the order of the compressed_len and uncompressed_len fields is reversed compared to the definition. Since all access to this index is positional as columns 2 and 3 as far as I could find, and the field types are the same, this doesn't end up mattering in actual usage. However, in memory in the index definition, the column names are incorrect, and this should be fixed to avoid future confusion or mishaps. Index creation/definition occurs in storage/innobase/dict/dict0crea.cc: 651 dict_index_t *dict_sdi_create_idx_in_mem(space_id_t space, bool space_discarded, 652 uint32_t in_flags, bool is_create) { ... 692 dict_mem_table_add_col(table, heap, "type", DATA_INT, 693 DATA_NOT_NULL | DATA_UNSIGNED, 4, true); 694 dict_mem_table_add_col(table, heap, "id", DATA_INT, 695 DATA_NOT_NULL | DATA_UNSIGNED, 8, true); 696 dict_mem_table_add_col(table, heap, "compressed_len", DATA_INT, 697 DATA_NOT_NULL | DATA_UNSIGNED, 4, true); 698 dict_mem_table_add_col(table, heap, "uncompressed_len", DATA_INT, 699 DATA_NOT_NULL | DATA_UNSIGNED, 4, true); 700 dict_mem_table_add_col(table, heap, "data", DATA_BLOB, DATA_NOT_NULL, 0, 701 true); Reading and writing occurs in storage/innobase/api/api0api.cc: 2716 static ib_tpl_t ib_sdi_create_insert_tuple(ib_crsr_t ib_crsr, 2717 const sdi_key_t *sdi_key, 2718 uint32_t uncomp_len, 2719 uint32_t comp_len, const void *sdi) { ... 2723 ib_tpl_t tuple = ib_clust_read_tuple_create(ib_crsr); 2724 ib_col_set_value(tuple, 0, &sdi_key->type, SDI_TYPE_LEN, false); 2725 ib_col_set_value(tuple, 1, &sdi_key->id, SDI_KEY_LEN, false); 2726 ib_col_set_value(tuple, 2, &uncomp_len, 4, false); 2727 ib_col_set_value(tuple, 3, &comp_len, 4, false); 2728 ib_col_set_value(tuple, 4, sdi, comp_len, false); and 2935 dberr_t ib_sdi_get(uint32_t tablespace_id, const ib_sdi_key_t *ib_sdi_key, 2936 void *comp_sdi, uint32_t *comp_sdi_len, 2937 uint32_t *uncomp_sdi_len, trx_t *trx) { ... 2975 ib_tuple_read_u32(tuple, 2, uncomp_sdi_len); 2976 ib_tuple_read_u32(tuple, 3, comp_sdi_len); How to repeat: Examine the code. Suggested fix: Reverse the order of the compressed_len and uncompressed_len fields in dict_sdi_create_idx_in_mem() in storage/innobase/dict/dict0crea.cc.