Why is Solr so much faster than Postgres?

Question

I recently switched from Postgres to Solr and saw a ~50x speed up in our queries. The queries we run involve multiple ranges, and our data is vehicle listings. For example: \"Fi

Answer 1

This biggest difference is that a Lucene/Solr index is like a single-table database without any support for relational queries (JOINs). Remember that an index is usually only there to support search and not to be the primary source of the data. So your database may be in "third normal form" but the index will be completely be de-normalized and contain mostly just the data needed to be searched.

Another possible reason is generally databases suffer from internal fragmentation, they need to perform too much semi-random I/O tasks on huge requests.

What that means is, for example, considering the index architecture of a databases, the query leads to the indexes which in turn lead to the data. If the data to recover is widely spread, the result will take long and that seems to be what happens in databases.