these searchers incorrectly called Next() on their underlying
searcher, instead of Advance(). this can cause values to be
returned with an ID less than the one that was Advanced() to,
which violates the contract, and causes other incorrect behavior.
fixes#342
the behavior has been defined in a way that is compatible with
encoding/json. this behavior is as follows:
anonymous fields which are structs will have struct fields get
field names as if they were directly in the parent struct.
anonymous fields which are not structs, or which are interfaces
which may or may not point to structs will get field names that
correspond to the name of the type
the exception to the rules above is that you can always override
this behavior by using a JSON struct tag
fixes#101
change cjk bigram analyzer to work with multi-rune terms
add cjk width filter replaces full unicode normailzation
these changes make the cjk analyzer behave more like elasticsearch
they also remove the depenency on the whitespace analyzer
which is now free to also behave more like lucene/es
fixes#33
fixes#378
this bug was introduced by:
f2aba116c4
theory of operation for this collector (top N, skip K)
- collect the highest scoring N+K results
- if K > 0, skip K and return the next N
internal details
- the top N+K are kept in a list
- the list is ordered from lowest scoring (first) to highest scoring (last)
- as a hit comes in, we find where this new hit would fit into this list
- if this caused the list to get too big, trim off the head (lowest scoring hit)
theory of the optimization
- we were not tracking the lowest score in the list
- so if the score was lower than the lowest score, we would add/remove it
- by keeping track of the lowest score in the list, we can avoid these ops
problem with the optimization
- the optimization worked by returning early
- by returning early there was a subtle change to documents which had the same score
- the reason is that which docs end up in the top N+K changed by returning early
- why was that? docs are coming in, in order by key ascending
- when finding the correct position to insert a hit into the list, we checked <, not <= the score
- this has the subtle effect that docs with the same score end up in reverse order
for example consider the following in progress list:
doc ids [ c a b ]
scores [ 1 5 9 ]
if we now see doc d with score 5, we get:
doc ids [ c a d b ]
scores [ 1 5 5 9 ]
While that appears in order (a, d) it is actually reverse order, because when we
produce the top N we start at the end.
theory of the fix
- previous pagination depended on later hits with the same score "bumping" earlier
hits with the same score off the bottom of the list
- however, if we change the logic to <= instead of <, now the list in the previous
example would look like:
doc ids [ c d a b ]
scores [ 1 5 5 9 ]
- this small change means that now earlier (lower id) will score higher, and
thus we no longer depend on later hits bumping things down, which means returning
early is a valid thing to do
NOTE: this does depend on the hits coming back in order by ID. this is not
something strictly guaranteed, but it was the same assumption that allowed the
original behavior
This also has the side-effect that 2 hits with the same score come back in
ascending ID order, which is somehow more pleasing to me than reverse order.
parsing of date ranges in queries no longer consults the
index mapping. it was deteremined that this wasn't very useful
and led to overly complicated query syntax/behavior.
instead, applications get set the datetime parser used for
date range queries with the top-level config QueryDateTimeParser
also, we now support querying date ranges in the query string,
the syntax is:
field:>"date"
>,>=,<,<= operators are supported
the date must be surrounded by quotes
and must parse in the configured date format
regexp, fuzzy and numeric range searchers now check to see if
they will be exceeding a configured DisjunctionMaxClauseCount
and stop work earlier, this does a better job of avoiding
situations which consume all available memory for an operation
they cannot complete
