Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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None
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None
Description
rocksdb.type_varchar fails like this:
CURRENT_TEST: rocksdb.type_varchar
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--- /home/psergey/dev-git/10.2-mariarocks/storage/rocksdb/mysql-test/rocksdb/r/type_varchar.result 2016-10-28 08:55:37.056371707 +0000
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+++ /home/psergey/dev-git/10.2-mariarocks/storage/rocksdb/mysql-test/rocksdb/r/type_varchar.reject 2016-12-02 19:14:06.552690598 +0000
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@@ -721,7 +721,7 @@
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insert into t values (1, 'abcabcabcabcabcabcabcabcabcabcabc ');
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explain select 'email_i' as index_name, count(*) AS count from t force index(email_i);
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id select_type table type possible_keys key key_len ref rows Extra
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-1 SIMPLE t index NULL email_i 33 NULL # Using index
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+1 SIMPLE t ALL NULL NULL NULL NULL #
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select 'email_i' as index_name, count(*) AS count from t force index(email_i);
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index_name count
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email_i 1
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@@ -734,7 +734,7 @@
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insert into t values (1, 'a');
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explain select 'email_i' as index_name, count(*) AS count from t force index(email_i);
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id select_type table type possible_keys key key_len ref rows Extra
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-1 SIMPLE t index NULL email_i 33 NULL # Using index
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+1 SIMPLE t ALL NULL NULL NULL NULL #
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select 'email_i' as index_name, count(*) AS count from t force index(email_i);
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index_name count
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email_i 1
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Initially this was reported here:
https://jira.mariadb.org/browse/MDEV-9658?focusedCommentId=87896&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-87896
but in the current tree, I see the same field->part_of_key for both MariaDB and MySQL:
(gdb) p tables_arg->table->field[0]->part_of_key
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warning: can't find linker symbol for virtual table for `Field' value
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$89 = {map = 3}
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(gdb) p tables_arg->table->field[1]->part_of_key
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warning: can't find linker symbol for virtual table for `Field' value
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$90 = {map = 0}
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Attachments
Issue Links
- is part of
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MDEV-9658 Make MyRocks in MariaDB stable
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- Closed
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- relates to
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- Closed
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Activity
keys_for_keyread is set in
- MySQL: setup_key_part_field(), which is called from open_binary_frm(),
- MariaDB: TABLE_SHARE::init_from_binary_frm_image()
In both cases, this is a chunk of code like this:
if (field->key_length() == key_part->length &&
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!(field->flags & BLOB_FLAG))
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{
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if (handler_file->index_flags(key, i, 0) & HA_KEYREAD_ONLY)
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{
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share->keys_for_keyread.set_bit(key);
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field->part_of_key.set_bit(key);
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And when proceessing the email_i index from
create table t (id int primary key, email varchar(100), KEY email_i (email(30)));
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MySQL will execute the above code for id as the second key part. MariaDB won't, because of its "keys with partially-columns are not extended" property.
This is why the execution is different. This case is
- not related to MyRocks
- an edge case (how often does it happen that all key components are partial?)
I'll just update the test result.
At start of make_join_statistics:
MariaDB:(gdb) p tables_list.head()->table->covering_keys$306 = {map = 0}MySQL:(gdb) p table->covering_keys$94 = {map = 2}covering_keys is initially set in setup_table_map():
MySQL:(gdb) p table->s->keys_for_keyread$108 = {map = 3}MariaDB:(gdb) p table->s->keys_for_keyread$317 = {map = 1}In both cases, setup_table_map does this:
table->covering_keys= table->s->keys_for_keyread;