Implement a naive graph pruning algorithm #73
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
msm-code
force-pushed
the
feature/pseudo-pruning
branch
2 times, most recently
from
6a0aa2c
to
be8237c
Compare
Constants in OnDiskIndex.cpp explain it all: ``` // Maximum number of possible values for the edge to be considered. // If token has more than MAX_EDGE possible values, it will never start // or end a subgraph. This is to avoid starting a subquery with `??`. constexpr uint32_t MAX_EDGE = 16; // Maximum number of possible values for ngram to be considered. If ngram // has more than MAX_NGRAM possible values, it won't be included in the // graph and the graph will be split into one or more subgraphs. constexpr uint32_t MAX_NGRAM = 256 * 256; ``` Oh the one hand, this is far from perfect. For example there is a **huge** performance difference between: ``` BB CC ?? DD ?? EE FF ``` And ``` A? B? C? ?? D? E? F? ``` The first one will execute in miliseconds, while the second one will take a long time. Fair enough, the second is literally the worst case (I can't think of a more complex expression that won't be rejected, but they both have 4 `?`s in the worst ngram, while one runs in 233ms and the other in 4135ms. On the other hand, they all finish running successfully, and I guess that's what matters in the end (no DB crashes).
msm-code
force-pushed
the
feature/pseudo-pruning
branch
from
be8237c
to
6421855
Compare
icedevml
approved these changes
Apr 17, 2020
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Constants in OnDiskIndex.cpp explain it all:
Oh the one hand, this is far from perfect. For example there is a huge
performance difference between:
And
The first one will execute in miliseconds, while the second one will take a
long time. Fair enough, the second is literally the worst case (I can't think
of a more complex expression that won't be rejected), but they both have 4
?sin the worst ngram, while one runs in 233ms and the other in 4135ms.
On the other hand, they all finish running successfully, and I guess that's
what matters in the end (no DB crashes).