Hello,
I am getting weird behaviour with the number of results returned by the Completion Suggester
.
I have the following request body for example:
"suggest": {
"title": {
"prefix": "ja",
"completion": {
"field": "suggest",
"size": 10
}
}
}
If the index has only 1 shard ("number_of_shards": 1
), I sometimes get the size I specify, and sometimes less, depending on my luck.
For example, for a specific search I know for fact there are +50 matches, but if I use size=10
I get 9 or 10, and size=30
randomly returns 19 or 30.
If I increase the number of shards of this index, it starts behaving correctly and returns all the available results while respecting the size
parameter, i.e. if I pass 30 for the size, I get back 30 results back. But if it's only 1 shard, things are quite random.
I would like to understand the reason why this happens before I just increase the number of shards. Especially that according to the documentation, it is recommended to use a single shard:
"To get best performance for completions, it is recommended to index completions into a single shard index"
Suggesters | Elasticsearch Guide [8.11] | Elastic
I am using v7.12.