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fdc4779235
Storage engine independent support for column compression. TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT, VARCHAR and VARBINARY columns can be compressed. New COMPRESSED column attribute added: COMPRESSED[=<compression_method>] System variables added: column_compression_threshold column_compression_zlib_level column_compression_zlib_strategy column_compression_zlib_wrap Status variables added: Column_compressions Column_decompressions Limitations: - the only supported method currently is zlib - CSV storage engine stores data uncompressed on-disk even if COMPRESSED attribute is present - it is not possible to create indexes over compressed columns.
33 lines
1.1 KiB
C
33 lines
1.1 KiB
C
#ifndef FIELD_COMP_H_INCLUDED
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#define FIELD_COMP_H_INCLUDED
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/* Copyright (C) 2017 MariaDB Foundation
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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#define MAX_COMPRESSION_METHODS 16
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struct Compression_method
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{
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const char *name;
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uint (*compress)(THD *thd, char *to, const char *from, uint length);
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int (*uncompress)(String *to, const uchar *from, uint from_length,
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uint field_length);
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};
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extern Compression_method compression_methods[MAX_COMPRESSION_METHODS];
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#define zlib_compression_method (&compression_methods[8])
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#endif
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