Fixed bug with UPDATE/DELETE on UNIQUE key which could be NULL (3c82d4a2) · Commits · Software / OSDI20 Artifacts / mariadb

Docs/manual.texi

+24 −5

Original line number	Diff line number	Diff line
		@@ -27391,8 +27391,22 @@ master-slave relationship with @code{log-slave-updates} enabled.
		Note, however, that many queries will not work right in this kind of
		setup unless your client code is written to take care of the potential
		problems that can happen from updates that occur in different sequence
		on different servers. Note that the log format has changed in Version 3.23.26
		so that pre-3.23.26 slaves will not be able to read it.
		on different servers.

		This means that you can do a setup like the following:

		@example
		A -> B -> C -> A
		@end example

		This setup will only works if you only do non conflicting updates
		between the tables. In other words, if you insert data in A and C, you
		should never insert a row in A that may have a conflicting key with a
		row insert in C. You should also not update the sam rows on two servers
		if the order in which the updates are applied matters.

		Note that the log format has changed in Version 3.23.26 so that
		pre-3.23.26 slaves will not be able to read it.
		@item
		If the query on the slave gets an error, the slave thread will
		terminate, and a message will appear in the @code{.err} file. You should
		@@ -28847,9 +28861,11 @@ explicitely lock the table with @code{LOCK TABLES} or execute a command that
		will modify every row in the table, like @code{ALTER TABLE}.

		In @strong{MySQL} Version 3.23.7 and above, you can insert rows into
		@code{MyISAM} tables at the same time other threads are reading from
		the table. Note that currently this only works if there are no holes after
		deleted rows in the table at the time the insert is made.
		@code{MyISAM} tables at the same time other threads are reading from the
		table. Note that currently this only works if there are no holes after
		deleted rows in the table at the time the insert is made. When all holes
		has been filled with new data, concurrent inserts will automaticly be
		enabled again.

		Table locking enables many threads to read from a table at the same
		time, but if a thread wants to write to a table, it must first get
		@@ -42743,6 +42759,9 @@ not yet 100% confident in this code.
		@appendixsubsec Changes in release 3.23.37
		@itemize @bullet
		@item
		@code{UPDATE} and @code{DELETE} with @code{WHERE unique_key_part IS NULL}
		didn't update/delete all rows.
		@item
		Disabled @code{INSERT DELAYED} for tables that supports transactions.
		@item
		Fixed bug when using date functions on @code{TEXT}/@code{BLOB} column

mysql-test/r/null_key.result

+28 −0

Original line number	Diff line number	Diff line
		@@ -92,3 +92,31 @@ NULL 9 0
		NULL 9 0
		a b c
		6 6 0
		table type possible_keys key key_len ref rows Extra
		t1 ref idx1 idx1 5 const 1 where used
		table type possible_keys key key_len ref rows Extra
		t1 const idx1 idx1 5 const 1
		id
		101
		102
		105
		106
		109
		110
		id
		101
		102
		105
		106
		109
		110
		id uniq_id
		3 1
		4 2
		7 3
		8 4
		id uniq_id
		3 1
		4 2
		7 3
		8 4

mysql-test/t/null_key.test

+46 −0

Original line number	Diff line number	Diff line
		@@ -45,3 +45,49 @@ select * from t1 where (a is null or a = 7) and b=7 and c=0;
		select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
		select * from t1 where b like "6%";
		drop table t1;


		#
		# The following failed for Matt Loschert
		#

		DROP TABLE IF EXISTS t1,t2;
		CREATE TABLE t1 (
		id int(10) unsigned NOT NULL auto_increment,
		uniq_id int(10) unsigned default NULL,
		PRIMARY KEY (id),
		UNIQUE KEY idx1 (uniq_id)
		) TYPE=MyISAM;

		CREATE TABLE t2 (
		id int(10) unsigned NOT NULL auto_increment,
		uniq_id int(10) unsigned default NULL,
		PRIMARY KEY (id)
		) TYPE=MyISAM;

		INSERT INTO t1 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
		INSERT INTO t2 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);

		#
		# Check IS NULL optimization
		#
		explain select id from t1 where uniq_id is null;
		explain select id from t1 where uniq_id =1;
		#
		# Check updates
		#
		UPDATE t1 SET id=id+100 where uniq_id is null;
		UPDATE t2 SET id=id+100 where uniq_id is null;
		select id from t1 where uniq_id is null;
		select id from t2 where uniq_id is null;
		#
		# Delete all records from each table where the uniq_id field is null
		#
		DELETE FROM t1 WHERE uniq_id IS NULL;
		DELETE FROM t2 WHERE uniq_id IS NULL;
		#
		# Select what is left -- notice the difference
		#
		SELECT * FROM t1 ORDER BY uniq_id, id;
		SELECT * FROM t2 ORDER BY uniq_id, id;
		DROP table t1,t2;

mysys/Makefile.am

+6 −6

Original line number	Diff line number	Diff line
		@@ -49,9 +49,9 @@ EXTRA_DIST = thr_alarm.c thr_lock.c my_pthread.c my_thr_init.c \
		thr_mutex.c thr_rwlock.c
		libmysys_a_LIBADD = @THREAD_LOBJECTS@
		# test_fn removed 980815 since it not upp to date test_dir
		noinst_PROGRAMS = testhash test_charset @THREAD_LPROGRAMS@
		noinst_PROGRAMS = test_charset @THREAD_LPROGRAMS@
		# test_dir_DEPENDENCIES= $(LIBRARIES)
		testhash_DEPENDENCIES= $(LIBRARIES)
		# testhash_DEPENDENCIES= $(LIBRARIES)
		test_charset_DEPENDENCIES= $(LIBRARIES)
		EXTRA_PROGRAMS =
		DEFS = -DDEFAULT_BASEDIR=\"$(prefix)\" \
		@@ -81,17 +81,17 @@ FLAGS=$(DEFS) $(INCLUDES) $(CPPFLAGS) $(CFLAGS) @NOINST_LDFLAGS@
		#

		test_thr_alarm: thr_alarm.c $(LIBRARIES)
		$(CP) -f $(srcdir)/thr_alarm.c ./test_thr_alarm.c
		$(CP) $(srcdir)/thr_alarm.c ./test_thr_alarm.c
		$(LINK) $(FLAGS) -DMAIN ./test_thr_alarm.c $(LDADD) $(LIBS)
		$(RM) -f ./test_thr_alarm.*

		test_thr_lock: thr_lock.c $(LIBRARIES)
		$(CP) -f $(srcdir)/thr_lock.c test_thr_lock.c
		$(CP) $(srcdir)/thr_lock.c test_thr_lock.c
		$(LINK) $(FLAGS) -DMAIN ./test_thr_lock.c $(LDADD) $(LIBS)
		$(RM) -f ./test_thr_lock.*

		test_vsnprintf: my_vsnprintf.c $(LIBRARIES)
		$(CP) -f $(srcdir)/my_vsnprintf.c test_vsnprintf.c
		$(CP) $(srcdir)/my_vsnprintf.c test_vsnprintf.c
		$(LINK) $(FLAGS) -DMAIN ./test_vsnprintf.c $(LDADD) $(LIBS)
		$(RM) -f test_vsnprintf.*

		@@ -102,7 +102,7 @@ test_charset: test_charset.c $(LIBRARIES)
		$(LINK) $(FLAGS) -DMAIN $(srcdir)/test_charset.c $(LDADD) $(LIBS)

		testhash: testhash.c $(LIBRARIES)
		$(LINK) $(FLAGS) -DMAIN $(srcdir)/test_dir.c $(LDADD) $(LIBS)
		$(LINK) $(FLAGS) -DMAIN $(srcdir)/testhash.c $(LDADD) $(LIBS)

		# Don't update the files from bitkeeper
		%::SCCS/s.%

sql/field.cc

+1 −1

Original line number	Diff line number	Diff line
		@@ -3891,7 +3891,7 @@ String Field_blob::val_str(String val_buffer __attribute__((unused)),
		char *blob;
		memcpy_fixed(&blob,ptr+packlength,sizeof(char*));
		if (!blob)
		val_ptr->length(0);
		val_ptr->set("",0); // A bit safer than ->length(0)
		else
		val_ptr->set((const char*) blob,get_length(ptr));
		return val_ptr;