提交 be7b6d67 authored 作者: Thomas Mueller's avatar Thomas Mueller

Documentation

上级 1fb1a875
...@@ -371,7 +371,7 @@ H2 1.3, ...@@ -371,7 +371,7 @@ H2 1.3,
*9 When using MVCC (multi version concurrency).<br /> *9 When using MVCC (multi version concurrency).<br />
*10 Derby and HSQLDB *10 Derby and HSQLDB
<a href="http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29">don't hide data patterns well</a>.<br /> <a href="http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29">don't hide data patterns well</a>.<br />
*11 The MULTI_THREADED option is not enabled by default, and not yet supported when using MVCC.<br /> *11 The MULTI_THREADED option is not enabled by default, and with version 1.3.x not supported when using MVCC.<br />
*12 Derby doesn't support the <code>EXPLAIN</code> statement, but it supports runtime statistics and retrieving statement execution plans.<br /> *12 Derby doesn't support the <code>EXPLAIN</code> statement, but it supports runtime statistics and retrieving statement execution plans.<br />
*13 Derby doesn't support the syntax <code>LIMIT .. [OFFSET ..]</code>, however it supports <code>FETCH FIRST .. ROW[S] ONLY</code>.<br /> *13 Derby doesn't support the syntax <code>LIMIT .. [OFFSET ..]</code>, however it supports <code>FETCH FIRST .. ROW[S] ONLY</code>.<br />
*14 Using collations. *14 Using collations.
...@@ -853,15 +853,17 @@ other processes (that could reside on other computers as well) connect to the se ...@@ -853,15 +853,17 @@ other processes (that could reside on other computers as well) connect to the se
<h3>Multithreading Support</h3> <h3>Multithreading Support</h3>
<p> <p>
This database is multithreading-safe. That means, if an application is multi-threaded, it does not need This database is multithreading-safe.
to worry about synchronizing access to the database. Internally, most requests to the same database If an application is multi-threaded, it does not need to worry about synchronizing access to the database.
are synchronized. That means an application can use multiple threads that access the same database An application should normally use one connection per thread.
at the same time, however if one thread executes a long running query, the other threads This database synchronizes access to the same connection, but other databases may not do this.
need to wait. To get higher concurrency, you need to use multiple connections.
</p> </p>
<p> <p>
An application should normally use one connection per thread. This database synchronizes By default, requests to the same database are synchronized.
access to the same connection, but other databases may not do this. That means an application can use multiple threads that access the same database
at the same time, however if one thread executes a long running query, the other threads need to wait.
To enable concurrent database usage, see the setting <code>MULTI_THREADED</code>.
</p> </p>
<h3>Locking, Lock-Timeout, Deadlocks</h3> <h3>Locking, Lock-Timeout, Deadlocks</h3>
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