Skip to content

M
MariaDB
Switch branch/tag
  1. 28 Sep, 2010 3 commits
  3. 24 Sep, 2010 3 commits
  5. 22 Sep, 2010 1 commit
  7. 21 Sep, 2010 1 commit
  9. 17 Sep, 2010 1 commit
  11. 16 Sep, 2010 4 commits
    • Sergey Glukhov's avatar
      Bug#50402 Optimizer producing wrong results when using Index Merge on InnoDB · 31a38c0f
      Sergey Glukhov authored 
      Subselect executes twice, at JOIN::optimize stage
and at JOIN::execute stage. At optimize stage
Innodb prebuilt struct which is used for the
retrieval of column values is initialized in.
ha_innobase::index_read(), prebuilt->sql_stat_start is true.
After QUICK_ROR_INTERSECT_SELECT finished his job it
restores read_set/write_set bitmaps with initial values
and deactivates one of the handlers used by
QUICK_ROR_INTERSECT_SELECT in JOIN::cleanup
(it's the case when we reuse original handler as one of
 handlers required by QUICK_ROR_INTERSECT_SELECT object).
On second subselect execution inactive handler is activated
in  QUICK_RANGE_SELECT::reset, file->ha_index_init().
In ha_index_init Innodb prebuilt struct is reinitialized
with inappropriate read_set/write_set bitmaps. Further
reinitialization in ha_innobase::index_read() does not
happen as prebuilt->sql_stat_start is false.
It leads to partial retrieval of required field values
and we get a mix of field values from different records
in the record buffer.
The fix is to reset
read_set/write_set bitmaps as these values
are required for proper intialization of
internal InnoDB struct which is used for
the retrieval of column values
(see build_template(), ha_innodb.cc)


mysql-test/include/index_merge_ror_cpk.inc:
  test case
mysql-test/r/index_merge_innodb.result:
  test case
mysql-test/r/index_merge_myisam.result:
  test case
sql/opt_range.cc:
  if ROR merge scan is used we need to reset
  read_set/write_set bitmaps as these values
  are required for proper intialization of
  internal InnoDB struct which is used for
  the retrieval of column values
  (see build_template(), ha_innodb.cc)
      31a38c0f
    • Magne Mahre's avatar
      Bug #54606 innodb fast alter table + pack_keys=0 prevents · ebd207ba
      Magne Mahre authored 
                 adding new indexes

A fast alter table requires that the existing (old) table
and indices are unchanged (i.e only new indices can be
added).  To verify this, the layout and flags of the old
table/indices are compared for equality with the new.

The PACK_KEYS option is a no-op in InnoDB, but the flag
exists, and is used in the table compare.  We need to
check this (table) option flag before deciding whether an 
index should be packed or not.  If the table has
explicitly set PACK_KEYS to 0, the created indices should
not be marked as packed/packable.
      ebd207ba
    • Dmitry Shulga's avatar
      Fixed bug#42503 - "Lost connection" errors when using · 0c91b53d
      Dmitry Shulga authored 
      compression protocol.

The loss of connection was caused by a malformed packet
sent by the server in case when query cache was in use.
When storing data in the query cache, the query  cache
memory allocation algorithm had a tendency to reduce
the amount of memory block necessary to store a result
set, up to finally storing the entire result set in a single
block. With a significant result set, this memory block
could turn out to be quite large - 30, 40 MB and on.
When such a result set was sent to the client, the entire
memory block was compressed and written to network as a
single network packet. However, the length of the
network packet is limited by 0xFFFFFF (16MB), since
the packet format only allows 3 bytes for packet length.
As a result, a malformed, overly large packet
with truncated length would be sent to the client
and break the client/server protocol.

The solution is, when sending result sets from the query
cache, to ensure that the data is chopped into
network packets of size <= 16MB, so that there
is no corruption of packet length. This solution,
however, has a shortcoming: since the result set
is still stored in the query cache as a single block,
at the time of sending, we've lost boundaries of individual
logical packets (one logical packet = one row of the result
set) and thus can end up sending a truncated logical
packet in a compressed network packet.

As a result, on the client we may require more memory than 
max_allowed_packet to keep, both, the truncated
last logical packet, and the compressed next packet.
This never (or in practice never) happens without compression,
since without compression it's very unlikely that
a) a truncated logical packet would remain on the client
when it's time to read the next packet
b) a subsequent logical packet that is being read would be
so large that size-of-new-packet + size-of-old-packet-tail >
max_allowed_packet.
To remedy this issue, we send data in 1MB sized packets,
that's below the current client default of 16MB for
max_allowed_packet, but large enough to ensure there is no
unnecessary overhead from too many syscalls per result set.


sql/net_serv.cc:
  net_realloc() modified: consider already used memory
  when compare packet buffer length
sql/sql_cache.cc:
  modified Query_cache::send_result_to_client: send result to client
  in chunks limited by 1 megabyte.
      0c91b53d
    • Mikael Ronstrom's avatar
      Updated build_mccge.sh and added support for more cpu's in check-cpu · 0876ef05
      Mikael Ronstrom authored
      0876ef05
  13. 15 Sep, 2010 26 commits
  15. 14 Sep, 2010 1 commit
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7