# Does aliasing require reindexing?
**URL:** https://discuss.elastic.co/t/does-aliasing-require-reindexing/9788
**Category:** Elasticsearch
**Created:** [November 21, 2012, 10:56pm UTC](https://discuss.elastic.co/t/does-aliasing-require-reindexing/9788 "2012-11-21T22:56:23Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@T\_Vinod\_Gupta](https://discuss.elastic.co/u/T_Vinod_Gupta)
#### Post date: [November 21, 2012, 10:56pm UTC](https://discuss.elastic.co/t/does-aliasing-require-reindexing/9788/1 "2012-11-21T22:56:23Z")
hi,
i just wanted to confirm something.. if i already have a bunch of data for
different users in an index with 5 shards and now i want to create an alias
for each user with a filter and routing parameter associated with it, then
i have to reindex the data for that user using either the new index name or
routing parameter, right? otherwise, data that is not in the routed shard
will never come up in searches against that alias index.
thanks
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### Author:  [@Clinton\_Gormley](https://discuss.elastic.co/u/Clinton_Gormley)
#### Post date: [November 22, 2012, 10:00am UTC](https://discuss.elastic.co/t/does-aliasing-require-reindexing/9788/2 "2012-11-22T10:00:09Z")
On Wed, 2012-11-21 at 14:56 -0800, T Vinod Gupta wrote:
> hi,
> i just wanted to confirm something.. if i already have a bunch of data
> for different users in an index with 5 shards and now i want to create
> an alias for each user with a filter and routing parameter associated
> with it, then i have to reindex the data for that user using either
> the new index name or routing parameter, right? otherwise, data that
> is not in the routed shard will never come up in searches against that
> alias index.
Correct.
clint
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 3:03am UTC](https://discuss.elastic.co/t/does-aliasing-require-reindexing/9788/3 "2017-07-06T03:03:16Z")