From: Mike Bayer Date: Wed, 12 Apr 2017 20:28:55 +0000 (-0400) Subject: - typos and formatting X-Git-Tag: rel_1_2_0b1~100 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3b4042c9c5f05e1354dc5ab87803026a757fcfc;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git - typos and formatting Change-Id: I88a304e315b68eded31e91da04265da583bc417b --- diff --git a/doc/build/faq/performance.rst b/doc/build/faq/performance.rst index 61c0d6ea22..d9684a44cb 100644 --- a/doc/build/faq/performance.rst +++ b/doc/build/faq/performance.rst @@ -483,11 +483,11 @@ is occurring: mailing list support is at: http://www.sqlalchemy.org/support.html#mailinglist The cache works by creating a cache key that can uniquely identify the -combination of a specific **dialect** and a specific **Core SQL expression**. +combination of a specific dialect and a specific Core SQL expression. A cache key that already exists in the cache will reuse the already-compiled SQL expression. A cache key that doesn't exist will create a *new* entry in the dictionary. When this dictionary reaches the configured threshhold, -the LRU cache will *trim the size* of the cache back down by a certain percentage. +the LRU cache will trim the size of the cache back down by a certain percentage. It is important to understand that from the above, **a compiled cache that is reaching its size limit will perform badly.** This is because not only @@ -498,7 +498,7 @@ its size back down. The primary reason the compiled caches can grow is due to the **antipattern of using a new Engine for every operation**. Because the compiled cache must key on the :class:`.Dialect` associated with an :class:`.Engine`, -calling :func`.create_engine` many times in an application will establish +calling :func:`.create_engine` many times in an application will establish new cache entries for every engine. Because the cache is self-trimming, the application won't grow in size unbounded, however the application should be repaired to not rely on an unbounded number of :class:`.Engine`