openstack/neutron
Code Issues Proposed changes

Merge "Fix the duplicated references"

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Jenkins 2016-01-17 20:36:42 +00:00 committed by Gerrit Code Review
commit ab68da426f
1 changed files with 3 additions and 3 deletions
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doc/source/devref/effective_neutron.rst
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@ -115,13 +115,13 @@ Document common pitfalls as well as good practices done during database developm
lazy='joined' parameter to the relationship so the related objects are loaded lazy='joined' parameter to the relationship so the related objects are loaded
as part of the same query. Otherwise, the default method is 'select', which as part of the same query. Otherwise, the default method is 'select', which
emits a new DB query to retrieve each related object adversely impacting emits a new DB query to retrieve each related object adversely impacting
performance. For example, see `this patch <https://review.openstack.org/#/c/88665/>`_ performance. For example, see `patch 88665 <https://review.openstack.org/#/c/88665/>`_
which resulted in a significant improvement since router retrieval functions which resulted in a significant improvement since router retrieval functions
always include the gateway interface. always include the gateway interface.
* Conversely, do not use lazy='joined' if the relationship is only used in * Conversely, do not use lazy='joined' if the relationship is only used in
corner cases because the JOIN statement comes at a cost that may be corner cases because the JOIN statement comes at a cost that may be
significant if the relationship contains many objects. For example, see significant if the relationship contains many objects. For example, see
`this patch <https://review.openstack.org/#/c/168214/>`_ which reduced a `patch 168214 <https://review.openstack.org/#/c/168214/>`_ which reduced a
subnet retrieval by ~90% by avoiding a join to the IP allocation table. subnet retrieval by ~90% by avoiding a join to the IP allocation table.
* When writing extensions to existing objects (e.g. Networks), ensure that * When writing extensions to existing objects (e.g. Networks), ensure that
they are written in a way that the data on the object can be calculated they are written in a way that the data on the object can be calculated
@ -129,7 +129,7 @@ Document common pitfalls as well as good practices done during database developm
is performed once in bulk during a list operation. Otherwise a list call is performed once in bulk during a list operation. Otherwise a list call
for a 1000 objects will change from a constant small number of DB queries for a 1000 objects will change from a constant small number of DB queries
to 1000 DB queries. For example, see to 1000 DB queries. For example, see
`this patch <https://review.openstack.org/#/c/257086/>`_ which changed the `patch 257086 <https://review.openstack.org/#/c/257086/>`_ which changed the
availability zone code from the incorrect style to a database friendly one. availability zone code from the incorrect style to a database friendly one.
System development System development