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From "Yonik Seeley" <yo...@apache.org>
Subject Re: Searching multiple indices (solr newbie)
Date Tue, 09 Jan 2007 20:32:33 GMT
On 1/9/07, Mekin Maheshwari <mekin.m@gmail.com> wrote:
> Is there any cost to using dynamicFields ?

Very little.  A dynamicField is created on demand during indexing or
searching, but the SchemaField created only has 4 pointers in it.

dynamicField is a Solr concept, not a Lucene one... so the only other
impacts are due to having many fields:
1) some info about each field is kept in memory, but not too much
2) a possibly larger term index since field1:val1 and field2:val1 are
separate terms
3) merging segments goes through the fields in a linear fasion
4) norms!

If norms are omitted, you could have thousands of fields without much impact.

> Any disadvantage ?
> Do dynamic fields have norms turned on by default ?

Like any other field in this regard... omitNorms needs to be set to
"true" on the fieldtype or the field.

> Can I boost on them at query time ?

Yes, norms are only related to index-time boosts and length normalization.

> I might end up exploding the size of the index.
>
>
> In general I felt that smaller indexes with different requirements
> might be more flexible than 1 large index (Would a  3G index
> considered large ?). eg. backing up the index, deploying a fresh
> index, etc. But Solr does address most of these.

That's medium sized.  Shouldn't be too big for a single index if
that's the route you want to take.

> The assumption could be baseless now & I should probably consider
> having 1 index for all categories.

-Yonik

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