1> 2 lakh at most. If the standard background merging is going on it may be less than that.
2> Some, but whether you notice or not is an open question. In an index with only 10 lakh docs, it's unlikely even having 50% deleted documents is going to make much of a difference. 3> Yes, the deleted docs are in segment until it's merged away. Lucene is very efficient (according to Mike McCandless) at skipping deleted docs. 4> It rewrites all segments, purging deleted documents. However, it has some pitfalls, see: https://lucidworks.com/2017/10/13/segment-merging-deleted-documents-optimize-may-bad/. In general it's simply not recommended to optimize. There is a Solr JIRA discussing this in detail, but I can't get to the site to link it right now. In general, as an index is updated segments are merged together and during that process any deleted documents are purged. Two resources: https://lucidworks.com/2013/08/23/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/ See the third animation TieredMergePolicy which is the default here: http://blog.mikemccandless.com/2011/02/visualizing-lucenes-segment-merges.html Best, Erick On Tue, Oct 31, 2017 at 4:40 AM, kshitij tyagi <kshitij.shopcl...@gmail.com> wrote: > Hi, > > I am using atomic update to update one of the fields, I want to know : > > 1. if total docs in core are 10 lakh and I partially update 2 lakhs docs > then what will be the number of deleted docs? > > 2. Does higher number of deleted docs have affect on query time? means does > query time increases if deleted docs are more > > 3. Are deleted docs present in segment? during query execution does deleted > docs are traversed. > > 4. What doe optimized button on solr admin does exactly. > > Help is much appreciated. > > Regards, > Kshitij
