On 8/12/2018 4:39 AM, Zahra Aminolroaya wrote:
Could we say that docvalue technique is better for sorting and faceting and
inverted index one is better for searching?
Yes. That is how things work.
If docValues do not exist, then an equivalent data structure must be
built in heap memory *from* the inverted index in order for faceting or
sorting to take place. When docValues are present, Solr can just read
the data directly instead of generating it. If there is plenty of spare
memory for the OS to cache data, this is faster. It also uses less Java
heap memory.
Will I lose anything if I only use docvalue?
Does docvalue technique have better performance?
From what I understand, it actually is possible to search when
docValues are present but the inverted index isn't, assuming that what
you're searching for is the full value of the field, not an individual
word. I have been informed that the performance of such a search is
absolutely terrible.
Thanks,
Shawn
