diff options
Diffstat (limited to 'lib/stdlib/doc/src/dets.xml')
| -rw-r--r-- | lib/stdlib/doc/src/dets.xml | 63 |
1 files changed, 14 insertions, 49 deletions
diff --git a/lib/stdlib/doc/src/dets.xml b/lib/stdlib/doc/src/dets.xml index 3b134d00b7..eb6e32aecf 100644 --- a/lib/stdlib/doc/src/dets.xml +++ b/lib/stdlib/doc/src/dets.xml @@ -100,18 +100,12 @@ provided by Dets, neither is the limited support for concurrent updates that makes a sequence of <c>first</c> and <c>next</c> calls safe to use on fixed ETS tables. Both these - features will be provided by Dets in a future release of + features may be provided by Dets in a future release of Erlang/OTP. Until then, the Mnesia application (or some user-implemented method for locking) must be used to implement safe concurrency. Currently, no Erlang/OTP library has support for ordered disk-based term storage.</p> - <p>Two versions of the format used for storing objects on file are - supported by Dets. The first version, 8, is the format always used - for tables created by Erlang/OTP R7 and earlier. The second version, 9, - is the default version of tables created by Erlang/OTP R8 (and later - releases). Erlang/OTP R8 can create version 8 tables, and convert version - 8 tables to version 9, and conversely, upon request.</p> <p>All Dets functions return <c>{error, Reason}</c> if an error occurs (<seealso marker="#first/1"><c>first/1</c></seealso> and <seealso marker="#next/2"><c>next/2</c></seealso> are exceptions, they @@ -190,9 +184,6 @@ <datatype> <name name="type"/> </datatype> - <datatype> - <name name="version"/> - </datatype> </datatypes> <funcs> @@ -385,19 +376,14 @@ <p><c>{bchunk_format, binary()}</c> - An opaque binary describing the format of the objects returned by <c>bchunk/2</c>. The binary can be used as argument to - <c>is_compatible_chunk_format/2</c>. Only available for - version 9 tables.</p> + <c>is_compatible_chunk_format/2</c>.</p> </item> <item> <p><c>{hash, Hash}</c> - Describes which BIF is used to calculate the hash values of the objects stored in the - <c>dets</c> table. Possible values of <c>Hash</c>:</p> + Dets table. Possible values of <c>Hash</c>:</p> <list> <item> - <p><c>hash</c> - Implies that the <c>erlang:hash/2</c> BIF - is used.</p> - </item> - <item> <p><c>phash</c> - Implies that the <c>erlang:phash/2</c> BIF is used.</p> </item> @@ -413,8 +399,7 @@ </item> <item> <p><c>{no_keys, integer >= 0()}</c> - The number of different - keys stored in the table. Only available for version 9 - tables.</p> + keys stored in the table.</p> </item> <item> <p><c>{no_objects, integer >= 0()}</c> - The number of objects @@ -424,8 +409,7 @@ <p><c>{no_slots, {Min, Used, Max}}</c> - The number of slots of the table. <c>Min</c> is the minimum number of slots, <c>Used</c> is the number of currently used slots, - and <c>Max</c> is the maximum number of slots. Only - available for version 9 tables.</p> + and <c>Max</c> is the maximum number of slots.</p> </item> <item> <p><c>{owner, pid()}</c> - The pid of the process that @@ -466,10 +450,6 @@ time warp safe</seealso>. Time warp safe code must use <c>safe_fixed_monotonic_time</c> instead.</p> </item> - <item> - <p><c>{version, integer()}</c> - The version of the format of - the table.</p> - </item> </list> </desc> </func> @@ -662,8 +642,8 @@ ok objects at a time, until at least one object matches or the end of the table is reached. The default, indicated by giving <c><anno>N</anno></c> the value <c>default</c>, is to let - the number of objects vary depending on the sizes of the objects. If - <c><anno>Name</anno></c> is a version 9 table, all objects with the + the number of objects vary depending on the sizes of the objects. + All objects with the same key are always matched at the same time, which implies that more than <anno>N</anno> objects can sometimes be matched.</p> <p>The table is always to be protected using @@ -743,9 +723,9 @@ ok end of the table is reached. The default, indicated by giving <c><anno>N</anno></c> the value <c>default</c>, is to let the number - of objects vary depending on the sizes of the objects. If - <c><anno>Name</anno></c> is a version 9 table, all matching objects - with the same key are always returned in the same reply, which implies + of objects vary depending on the sizes of the objects. All + matching objects with the same key are always returned + in the same reply, which implies that more than <anno>N</anno> objects can sometimes be returned.</p> <p>The table is always to be protected using <seealso marker="#safe_fixtable/2"><c>safe_fixtable/2</c></seealso> @@ -842,8 +822,7 @@ ok maximal value. Notice that a higher value can increase the table fragmentation, and a smaller value can decrease the fragmentation, at - the expense of execution time. Only available for version - 9 tables.</p> + the expense of execution time.</p> </item> <item> <p><c>{min_no_slots, </c><seealso marker="#type-no_slots"> @@ -880,12 +859,7 @@ ok FileName}}</c> is returned if the table must be repaired.</p> <p>Value <c>force</c> means that a reparation is made even if the table is properly closed. - This is how to convert tables created by older versions of - STDLIB. An example is tables hashed with the deprecated - <c>erlang:hash/2</c> BIF. Tables created with Dets from - STDLIB version 1.8.2 or later use function - <c>erlang:phash/2</c> or function <c>erlang:phash2/1</c>, - which is preferred.</p> + This is a seldom needed option.</p> <p>Option <c>repair</c> is ignored if the table is already open.</p> </item> <item> @@ -893,15 +867,6 @@ ok <c>type()</c></seealso><c>}</c> - The table type. Defaults to <c>set</c>.</p> </item> - <item> - <p><c>{version, </c><seealso marker="#type-version"> - <c>version()</c></seealso><c>}</c> - The version of the format - used for the table. Defaults to <c>9</c>. Tables on the format - used before Erlang/OTP R8 can be created by specifying value - <c>8</c>. A version 8 table can be converted to a version 9 - table by specifying options <c>{version,9}</c> - and <c>{repair,force}</c>.</p> - </item> </list> </desc> </func> @@ -1041,8 +1006,8 @@ ok a time, until at least one object matches or the end of the table is reached. The default, indicated by giving <c><anno>N</anno></c> the value <c>default</c>, is to let the number - of objects vary depending on the sizes of the objects. If - <c><anno>Name</anno></c> is a version 9 table, all objects with the + of objects vary depending on the sizes of the objects. All + objects with the same key are always handled at the same time, which implies that the match specification can be applied to more than <anno>N</anno> objects.</p> |