Database Reference
In-Depth Information
Figure 4-4. Performance with hierarchical documents
Separate documents by granularity level
Pre-allocation of documents helps our update speed significantly, but we still have a problem
when querying data for long, multiday periods like months or quarters. In such cases, storing
daily aggregates in a higher-level document can speed up these queries.
Thisintroducesasecondsetofupsertoperationstothedatacollection andaggregationportion
of your application, but the gains in reduction of disk seeks on the queries should be worth the
costs. Consider the example schema presented in
Example 4-1
and
Example 4-2
.
Example 4-1. Daily statistics
{
_id
:
"20101010/site-1/apache_pb.gif"
,
metadata
:
{
date
:
ISODate
(
"2000-10-10T00:00:00Z"
),
site
:
"site-1"
,
page
:
"/apache_pb.gif"
},
hourly
:
{
"0"
:
227850
,
"1"
:
210231
,
...
