On 9/13/2018 2:07 AM, Rekha wrote:
Hi Solr Team,
I am new to SOLR. I need following clarification from you.
How many documents can be stored in one core? Is
there any limit for number of fields per document? How many
Core’s can be created in on SOLR? Is there any other
limitation is there based on the Disk storage size? I mean some of the database has
the 10 GM limit, I have asked like that. Can we use SOLR as a
database?
You *can* use Solr as a database, but I wouldn't. It's not designed for
that role. Actual database software is better for that. If all you
need is simple data storage, Solr can handle that, but as soon as you
start talking about complex operations like JOIN, a real database is FAR
better. Solr is a search engine, and in my opinion, that's what it
should be used for.
The only HARD limit that Solr has is actually a Lucene limit. Lucene
uses the java "int" type for its internal document ID. Which means that
the absolute maximum number of documents in one Solr core is
2147483647. That's a little over two billion. You're likely to have
scalability problems long before you reach this number, though. Also,
this number includes deleted documents, so it's not a good idea to
actually get close to the limit. One rough rule of thumb that sometimes
gets used: If you have more than one hundred million documents in a
single core, you PROBABLY need to think about re-designing your setup.
Using a sharded index (which SolrCloud can do a lot easier than
standalone Solr) removes the two billion document limitation for an
index -- by spreading the index across multiple Solr cores.
As for storage, you should have enough disk space available so that your
index data can triple in size temporarily. This is not a joke -- that's
really the recommendation. The way that Lucene operates requires that
you have at least *double* capacity, but there are real world situations
in which the index can triple in size.
Running with really big indexes means that you also need a lot of
memory. Good performance with Solr requires that the operating system
has enough memory to effectively cache the often-used parts of the index.
https://wiki.apache.org/solr/SolrPerformanceProblems#RAM
Thanks,
Shawn
