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Allow ADD COLUMN anywhere in a table, not only adding as the last column. Allow instant DROP COLUMN and instant changing the order of columns. The added columns will always be added last in clustered index records. In new records, instantly dropped columns will be stored as NULL or empty when possible. Information about dropped and reordered columns will be written in a metadata BLOB (mblob), which is stored before the first 'user' field in the hidden metadata record at the start of the clustered index. The presence of mblob is indicated by setting the delete-mark flag in the metadata record. The metadata BLOB stores the number of clustered index fields, followed by an array of column information for each field. For dropped columns, we store the NOT NULL flag, the fixed length, and for variable-length columns, whether the maximum length exceeded 255 bytes. For non-dropped columns, we store the column position. Unlike with MDEV-11369, when a table becomes empty, it cannot be converted back to the canonical format. The reason for this is that other threads may hold cached objects such as row_prebuilt_t::ins_node that could refer to dropped or reordered index fields. For instant DROP COLUMN and ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC, we must store the n_core_null_bytes in the root page, so that the chain of node pointer records can be followed in order to reach the leftmost leaf page where the metadata record is located. If the mblob is present, we will zero-initialize the strings "infimum" and "supremum" in the root page, and use the last byte of "supremum" for storing the number of null bytes (which are allocated but useless on node pointer pages). This is necessary for btr_cur_instant_init_metadata() to be able to navigate to the mblob. If the PRIMARY KEY contains any variable-length column and some nullable columns were instantly dropped, the dict_index_t::n_nullable in the data dictionary could be smaller than it actually is in the non-leaf pages. Because of this, the non-leaf pages could use more bytes for the null flags than the data dictionary expects, and we could be reading the lengths of the variable-length columns from the wrong offset, and thus reading the child page number from wrong place. This is the result of two design mistakes that involve unnecessary storage of data: First, it is nonsense to store any data fields for the leftmost node pointer records, because the comparisons would be resolved by the MIN_REC_FLAG alone. Second, there cannot be any null fields in the clustered index node pointer fields, but we nevertheless reserve space for all the null flags. Limitations (future work): MDEV-17459 Allow instant ALTER TABLE even if FULLTEXT INDEX exists MDEV-17468 Avoid table rebuild on operations on generated columns MDEV-17494 Refuse ALGORITHM=INSTANT when the row size is too large btr_page_reorganize_low(): Preserve any metadata in the root page. Call lock_move_reorganize_page() only after restoring the "infimum" and "supremum" records, to avoid a memcmp() assertion failure. dict_col_t::DROPPED: Magic value for dict_col_t::ind. dict_col_t::clear_instant(): Renamed from dict_col_t::remove_instant(). Do not assert that the column was instantly added, because we sometimes call this unconditionally for all columns. Convert an instantly added column to a "core column". The old name remove_instant() could be mistaken to refer to "instant DROP COLUMN". dict_col_t::is_added(): Rename from dict_col_t::is_instant(). dtype_t::metadata_blob_init(): Initialize the mblob data type. dtuple_t::is_metadata(), dtuple_t::is_alter_metadata(), upd_t::is_metadata(), upd_t::is_alter_metadata(): Check if info_bits refer to a metadata record. dict_table_t::instant: Metadata about dropped or reordered columns. dict_table_t::prepare_instant(): Prepare ha_innobase_inplace_ctx::instant_table for instant ALTER TABLE. innobase_instant_try() will pass this to dict_table_t::instant_column(). On rollback, dict_table_t::rollback_instant() will be called. dict_table_t::instant_column(): Renamed from instant_add_column(). Add the parameter col_map so that columns can be reordered. Copy and adjust v_cols[] as well. dict_table_t::find(): Find an old column based on a new column number. dict_table_t::serialise_columns(), dict_table_t::deserialise_columns(): Convert the mblob. dict_index_t::instant_metadata(): Create the metadata record for instant ALTER TABLE. Invoke dict_table_t::serialise_columns(). dict_index_t::reconstruct_fields(): Invoked by dict_table_t::deserialise_columns(). dict_index_t::clear_instant_alter(): Move the fields for the dropped columns to the end, and sort the surviving index fields in ascending order of column position. ha_innobase::check_if_supported_inplace_alter(): Do not allow adding a FTS_DOC_ID column if a hidden FTS_DOC_ID column exists due to FULLTEXT INDEX. (This always required ALGORITHM=COPY.) instant_alter_column_possible(): Add a parameter for InnoDB table, to check for additional conditions, such as the maximum number of index fields. ha_innobase_inplace_ctx::first_alter_pos: The first column whose position is affected by instant ADD, DROP, or changing the order of columns. innobase_build_col_map(): Skip added virtual columns. prepare_inplace_add_virtual(): Correctly compute num_to_add_vcol. Remove some unnecessary code. Note that the call to innodb_base_col_setup() should be executed later. commit_try_norebuild(): If ctx->is_instant(), let the virtual columns be added or dropped by innobase_instant_try(). innobase_instant_try(): Fill in a zero default value for the hidden column FTS_DOC_ID (to reduce the work needed in MDEV-17459). If any columns were dropped or reordered (or added not last), delete any SYS_COLUMNS records for the following columns, and insert SYS_COLUMNS records for all subsequent stored columns as well as for all virtual columns. If any virtual column is dropped, rewrite all virtual column metadata. Use a shortcut only for adding virtual columns. This is because innobase_drop_virtual_try() assumes that the dropped virtual columns still exist in ctx->old_table. innodb_update_cols(): Renamed from innodb_update_n_cols(). innobase_add_one_virtual(), innobase_insert_sys_virtual(): Change the return type to bool, and invoke my_error() when detecting an error. innodb_insert_sys_columns(): Insert a record into SYS_COLUMNS. Refactored from innobase_add_one_virtual() and innobase_instant_add_col(). innobase_instant_add_col(): Replace the parameter dfield with type. innobase_instant_drop_cols(): Drop matching columns from SYS_COLUMNS and all columns from SYS_VIRTUAL. innobase_add_virtual_try(), innobase_drop_virtual_try(): Let the caller invoke innodb_update_cols(). innobase_rename_column_try(): Skip dropped columns. commit_cache_norebuild(): Update table->fts->doc_col. dict_mem_table_col_rename_low(): Skip dropped columns. trx_undo_rec_get_partial_row(): Skip dropped columns. trx_undo_update_rec_get_update(): Handle the metadata BLOB correctly. trx_undo_page_report_modify(): Avoid out-of-bounds access to record fields. Log metadata records consistently. Apparently, the first fields of a clustered index may be updated in an update_undo vector when the index is ID_IND of SYS_FOREIGN, as part of renaming the table during ALTER TABLE. Normally, updates of the PRIMARY KEY should be logged as delete-mark and an insert. row_undo_mod_parse_undo_rec(), row_purge_parse_undo_rec(): Use trx_undo_metadata. row_undo_mod_clust_low(): On metadata rollback, roll back the root page too. row_undo_mod_clust(): Relax an assertion. The delete-mark flag was repurposed for ALTER TABLE metadata records. row_rec_to_index_entry_impl(): Add the template parameter mblob and the optional parameter info_bits for specifying the desired new info bits. For the metadata tuple, allow conversion between the original format (ADD COLUMN only) and the generic format (with hidden BLOB). Add the optional parameter "pad" to determine whether the tuple should be padded to the index fields (on ALTER TABLE it should), or whether it should remain at its original size (on rollback). row_build_index_entry_low(): Clean up the code, removing redundant variables and conditions. For instantly dropped columns, generate a dummy value that is NULL, the empty string, or a fixed length of NUL bytes, depending on the type of the dropped column. row_upd_clust_rec_by_insert_inherit_func(): On the update of PRIMARY KEY of a record that contained a dropped column whose value was stored externally, we will be inserting a dummy NULL or empty string value to the field of the dropped column. The externally stored column would eventually be dropped when purge removes the delete-marked record for the old PRIMARY KEY value. btr_index_rec_validate(): Recognize the metadata record. btr_discard_only_page_on_level(): Preserve the generic instant ALTER TABLE metadata. btr_set_instant(): Replaces page_set_instant(). This sets a clustered index root page to the appropriate format, or upgrades from the MDEV-11369 instant ADD COLUMN to generic ALTER TABLE format. btr_cur_instant_init_low(): Read and validate the metadata BLOB page before reconstructing the dictionary information based on it. btr_cur_instant_init_metadata(): Do not read any lengths from the metadata record header before reading the BLOB. At this point, we would not actually know how many nullable fields the metadata record contains. btr_cur_instant_root_init(): Initialize n_core_null_bytes in one of two possible ways. btr_cur_trim(): Handle the mblob record. row_metadata_to_tuple(): Convert a metadata record to a data tuple, based on the new info_bits of the metadata record. btr_cur_pessimistic_update(): Invoke row_metadata_to_tuple() if needed. Invoke dtuple_convert_big_rec() for metadata records if the record is too large, or if the mblob is not yet marked as externally stored. btr_cur_optimistic_delete_func(), btr_cur_pessimistic_delete(): When the last user record is deleted, do not delete the generic instant ALTER TABLE metadata record. Only delete MDEV-11369 instant ADD COLUMN metadata records. btr_cur_optimistic_insert(): Avoid unnecessary computation of rec_size. btr_pcur_store_position(): Allow a logically empty page to contain a metadata record for generic ALTER TABLE. REC_INFO_DEFAULT_ROW_ADD: Renamed from REC_INFO_DEFAULT_ROW. This is for the old instant ADD COLUMN (MDEV-11369) only. REC_INFO_DEFAULT_ROW_ALTER: The more generic metadata record, with additional information for dropped or reordered columns. rec_info_bits_valid(): Remove. The only case when this would fail is when the record is the generic ALTER TABLE metadata record. rec_is_alter_metadata(): Check if a record is the metadata record for instant ALTER TABLE (other than ADD COLUMN). NOTE: This function must not be invoked on node pointer records, because the delete-mark flag in those records may be set (it is garbage), and then a debug assertion could fail because index->is_instant() does not necessarily hold. rec_is_add_metadata(): Check if a record is MDEV-11369 ADD COLUMN metadata record (not more generic instant ALTER TABLE). rec_get_converted_size_comp_prefix_low(): Assume that the metadata field will be stored externally. In dtuple_convert_big_rec() during the rec_get_converted_size() call, it would not be there yet. rec_get_converted_size_comp(): Replace status,fields,n_fields with tuple. rec_init_offsets_comp_ordinary(), rec_get_converted_size_comp_prefix_low(), rec_convert_dtuple_to_rec_comp(): Add template<bool mblob = false>. With mblob=true, process a record with a metadata BLOB. rec_copy_prefix_to_buf(): Assert that no fields beyond the key and system columns are being copied. Exclude the metadata BLOB field. rec_convert_dtuple_to_metadata_comp(): Convert an alter metadata tuple into a record. row_upd_index_replace_metadata(): Apply an update vector to an alter_metadata tuple. row_log_allocate(): Replace dict_index_t::is_instant() with a more appropriate condition that ignores dict_table_t::instant. Only a table on which the MDEV-11369 ADD COLUMN was performed can "lose its instantness" when it becomes empty. After instant DROP COLUMN or reordering columns, we cannot simply convert the table to the canonical format, because the data dictionary cache and all possibly existing references to it from other client connection threads would have to be adjusted. row_quiesce_write_index_fields(): Do not crash when the table contains an instantly dropped column. Thanks to Thirunarayanan Balathandayuthapani for discussing the design and implementing an initial prototype of this. Thanks to Matthias Leich for testing.
264 lines
6.7 KiB
Plaintext
264 lines
6.7 KiB
Plaintext
SET @save_frequency= @@GLOBAL.innodb_purge_rseg_truncate_frequency;
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SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
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CREATE TABLE t1 (
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pk INT AUTO_INCREMENT PRIMARY KEY,
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c1 INT,
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c2 VARCHAR(255),
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c3 VARCHAR(255),
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c4 INT,
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c5 INT,
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c6 INT,
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c7 VARCHAR(255),
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c8 TIMESTAMP NULL
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) ENGINE=InnoDB;
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INSERT INTO t1 VALUES (NULL,1,NULL,'foo',NULL,1,NULL,NULL,'2011-11-11 00:00:00');
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ALTER TABLE t1 ADD COLUMN f INT;
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REPLACE INTO t1 (c7) VALUES ('bar');
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CREATE TABLE t2 (i INT PRIMARY KEY) ENGINE=InnoDB;
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INSERT INTO t2 VALUES (-1),(1);
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ALTER TABLE t2 ADD COLUMN j INT;
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BEGIN;
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DELETE FROM t2;
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ROLLBACK;
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TRUNCATE TABLE t2;
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INSERT INTO t2 VALUES (1,2);
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CREATE TABLE t3 (pk INT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB;
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INSERT INTO t3 () VALUES ();
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ALTER TABLE t3 ADD COLUMN f INT;
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UPDATE t3 SET pk = DEFAULT;
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SELECT * FROM t3;
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pk f
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0 NULL
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CREATE TABLE t4 (pk INT PRIMARY KEY) ENGINE=InnoDB;
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INSERT INTO t4 VALUES (0);
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ALTER TABLE t4 ADD COLUMN b INT;
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SELECT COUNT(*)>0 FROM INFORMATION_SCHEMA.COLUMNS
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LEFT JOIN t4 ON (NUMERIC_SCALE = pk);
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COUNT(*)>0
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1
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ALTER TABLE t4 ADD COLUMN c INT;
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CREATE TABLE t5 (i INT, KEY(i)) ENGINE=InnoDB;
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INSERT INTO t5 VALUES (-42);
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ALTER TABLE t5 ADD UNIQUE ui(i);
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ALTER TABLE t5 ADD COLUMN i2 INT, DROP INDEX i;
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CREATE TABLE t6 (i INT NOT NULL) ENGINE=InnoDB;
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INSERT INTO t6 VALUES (0);
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ALTER TABLE t6 ADD COLUMN j INT;
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TRUNCATE TABLE t6;
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INSERT INTO t6 VALUES (1,2);
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CREATE TABLE t7 (i INT) ENGINE=InnoDB;
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INSERT INTO t7 VALUES (1),(2),(3),(4),(5);
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ALTER TABLE t7 ADD t TEXT DEFAULT '';
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CREATE TABLE t8 (i INT) ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
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INSERT INTO t8 VALUES (NULL);
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ALTER TABLE t8 ADD c CHAR(3);
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SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL rebuilt WAIT_FOR dml';
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ALTER TABLE t8 FORCE;
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connect dml,localhost,root,,;
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SET DEBUG_SYNC='now WAIT_FOR rebuilt';
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BEGIN;
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INSERT INTO t8 SET i=1;
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UPDATE t8 SET i=ISNULL(i);
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ROLLBACK;
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SET DEBUG_SYNC='now SIGNAL dml';
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connection default;
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SET DEBUG_SYNC='RESET';
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CREATE TABLE t9 (
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pk INT AUTO_INCREMENT PRIMARY KEY,
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c1 BIGINT UNSIGNED,
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c2 TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP,
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c3 BIGINT,
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c4 VARCHAR(257) CHARACTER SET utf8,
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c5 TINYINT UNSIGNED,
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c6 TINYINT,
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c7 VARCHAR(257) CHARACTER SET latin1,
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c8 VARCHAR(257) CHARACTER SET binary
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) ENGINE=InnoDB;
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INSERT INTO t9 () VALUES ();
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ALTER TABLE t9 ADD COLUMN IF NOT EXISTS t TIMESTAMP NULL KEY;
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Warnings:
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Note 1061 Multiple primary key defined
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SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL rebuilt WAIT_FOR dml';
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OPTIMIZE TABLE t9;
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connection dml;
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SET DEBUG_SYNC='now WAIT_FOR rebuilt';
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BEGIN;
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INSERT INTO t9 () VALUES (),();
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UPDATE t9 SET t=current_timestamp();
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ROLLBACK;
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SET DEBUG_SYNC='now SIGNAL dml';
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disconnect dml;
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connection default;
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Table Op Msg_type Msg_text
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test.t9 optimize note Table does not support optimize, doing recreate + analyze instead
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test.t9 optimize status OK
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SET DEBUG_SYNC='RESET';
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CREATE TABLE t10 (pk INT DEFAULT 0 KEY) ENGINE=InnoDB;
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INSERT INTO t10 (pk) VALUES (1);
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ALTER TABLE t10 ADD c INT;
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TRUNCATE TABLE t10;
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INSERT INTO t10 VALUES (1,1),(2,2);
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ALTER TABLE t10 FORCE;
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CREATE TABLE t11 (
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c01 enum('a','b'),
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c02 bit,
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c03 blob,
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c04 enum('c','d'),
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c05 blob,
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c06 decimal,
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c07 char(1),
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c08 int,
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c09 char(1),
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c10 set('e','f'),
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c11 char(1),
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c12 float,
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c13 bit,
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c14 char(1),
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c15 int,
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c16 float,
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c17 decimal,
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c18 char(1) CHARACTER SET utf8 not null default '',
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c19 float,
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c20 set('g','h'),
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c21 char(1),
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c22 int,
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c23 int,
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c24 int,
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c25 set('i','j'),
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c26 decimal,
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c27 float,
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c28 char(1),
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c29 int,
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c30 enum('k','l'),
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c31 decimal,
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c32 char(1),
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c33 decimal,
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c34 bit,
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c35 enum('m','n'),
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c36 set('o','p'),
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c37 enum('q','r'),
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c38 blob,
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c39 decimal,
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c40 blob not null default '',
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c41 char(1),
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c42 int,
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c43 float,
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c44 float,
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c45 enum('s','t'),
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c46 decimal,
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c47 set('u','v'),
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c48 enum('w','x'),
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c49 set('y','z'),
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c50 float
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) ENGINE=InnoDB;
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INSERT INTO t11 () VALUES ();
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ALTER TABLE t11 ADD COLUMN f INT;
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INSERT INTO t11 () VALUES ();
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UPDATE t11 SET c22 = 1;
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InnoDB 0 transactions not purged
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DROP TABLE t1,t2,t3,t4,t5,t6,t7,t8,t9,t10,t11;
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#
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# MDEV-15060 Assertion in row_log_table_apply_op after instant ADD
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# when the table is emptied during subsequent ALTER TABLE
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#
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CREATE TABLE t1 (a INT) ENGINE=InnoDB;
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INSERT INTO t1 VALUES (NULL);
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ALTER TABLE t1 ADD COLUMN b INT NOT NULL;
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connect stop_purge,localhost,root;
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START TRANSACTION WITH CONSISTENT SNAPSHOT;
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connect ddl,localhost,root,,test;
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DELETE FROM t1;
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SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
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ALTER TABLE t1 FORCE;
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connection default;
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SET DEBUG_SYNC='now WAIT_FOR copied';
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BEGIN;
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INSERT INTO t1 SET b=1;
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ROLLBACK;
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connection stop_purge;
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COMMIT;
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connection default;
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InnoDB 2 transactions not purged
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SET DEBUG_SYNC='now SIGNAL logged';
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connection ddl;
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connection default;
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DROP TABLE t1;
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SET DEBUG_SYNC='RESET';
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#
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# MDEV-16131 Assertion failed in dict_index_t::instant_field_value()
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#
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CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
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INSERT INTO t1 SET a=0;
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ALTER TABLE t1 ADD COLUMN b INT NOT NULL DEFAULT 2, ADD COLUMN c INT;
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connection stop_purge;
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START TRANSACTION WITH CONSISTENT SNAPSHOT;
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connection default;
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DELETE FROM t1;
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connection ddl;
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SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
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ALTER TABLE t1 FORCE;
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connection stop_purge;
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COMMIT;
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connection default;
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SET DEBUG_SYNC = 'now WAIT_FOR copied';
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InnoDB 1 transactions not purged
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INSERT INTO t1 SET a=1;
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INSERT INTO t1 SET a=2,b=3,c=4;
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SET DEBUG_SYNC = 'now SIGNAL logged';
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connection ddl;
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connection default;
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SET DEBUG_SYNC = RESET;
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SELECT * FROM t1;
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a b c
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1 2 NULL
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2 3 4
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ALTER TABLE t1 DROP b, ALGORITHM=INSTANT;
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connection stop_purge;
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START TRANSACTION WITH CONSISTENT SNAPSHOT;
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connection default;
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DELETE FROM t1;
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connection ddl;
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SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
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ALTER TABLE t1 ADD COLUMN b INT NOT NULL DEFAULT 2 AFTER a, FORCE;
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disconnect stop_purge;
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connection default;
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SET DEBUG_SYNC = 'now WAIT_FOR copied';
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InnoDB 1 transactions not purged
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INSERT INTO t1 SET a=1;
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INSERT INTO t1 SET a=2,c=4;
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SET DEBUG_SYNC = 'now SIGNAL logged';
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connection ddl;
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UPDATE t1 SET b = b + 1 WHERE a = 2;
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connection default;
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SET DEBUG_SYNC = RESET;
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SELECT * FROM t1;
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a b c
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1 2 NULL
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2 3 4
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#
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# MDEV-15872 Crash in online ALTER TABLE...ADD PRIMARY KEY
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# after instant ADD COLUMN ... NULL
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#
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ALTER TABLE t1 ADD COLUMN d INT, ALGORITHM=INSTANT;
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UPDATE t1 SET d=1;
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connection ddl;
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SET DEBUG_SYNC='row_log_table_apply1_before SIGNAL copied WAIT_FOR logged';
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ALTER IGNORE TABLE t1 DROP PRIMARY KEY, ADD PRIMARY KEY (a,d);
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connection default;
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SET DEBUG_SYNC = 'now WAIT_FOR copied';
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BEGIN;
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INSERT INTO t1 SET a=3;
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ROLLBACK;
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SET DEBUG_SYNC = 'now SIGNAL logged';
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connection ddl;
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ERROR 22004: Invalid use of NULL value
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disconnect ddl;
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connection default;
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SET DEBUG_SYNC = RESET;
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SELECT * FROM t1;
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a b c d
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1 2 NULL 1
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2 3 4 1
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DROP TABLE t1;
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SET GLOBAL innodb_purge_rseg_truncate_frequency = @save_frequency;
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