Release notes v0.8

[pawan (Pawan Rawal)]

Here is the diff since v0.7.7

https://github.com/dgraph-io/dgraph/compare/release/v0.7.7...release/v0.8?expand=1

Features

Server

• Suppport has function.
• Support for variables in mutation blocks.
• Support for k shortest paths.

• [*] @michaelcompton @ashwin95r Could you please add an example in the docs?

• Support deletion of predicate.
• Support for uid_in function.

• [*] @michaelcompton please add docs.

• Add a directive to remove reflexive edges from results.

• [*] @michaelcompton docs please.

• Allow to use Dgraph as a library.
• Ability to monitor server metrics.

• [*] @janardhan we need docs for how to use Promotheus and Grafana.

Client

• Go client now supports an Unmarshal function which allows unmarshalling the protocol buffer response to a custom struct.
  • [*] @michaelcompton please add a link to docs or an example for this.
• Add support for storing and retrieving raw bytes.
  • [*] @michaelcompton Could we add this to other examples too if not already.
• Cleaner and more intuitive API for doing mutations.

Improvements

• Move away from RocksDB and get rid of CGO. Start using badger.
• Assign uids sequentially.
• Allow retrieving other children with @groupby.
• Allow aliases for math expressions.
• Support filtering using multiple tokens with eq.
  • [*] @michaelcompton could you please check if we can docs for this?
• Better language lists semantics. Issue #1010
• Add a uid function which can be used for filtering uids at any level.

• [*] @michaelcompton please add this in functions section with an example of how to use it at levels other than root.

• Allow adding @count indexes which allow for faster count comparison queries at the root.
• Optimisations in how we store Posting List data structure. Store uids separately.
• Allow specifying a max depth argument for the shortest path.
• Support for [month, day, hour] indexes for datetime datatype.

• [*] @michaelcompton docs, please.

• Get rid of lhmap and add an LRU Cache. We don’t do Stop the World anymore.

Changes (from v0.7.7)

• date type is no longer supported as a schema type in Dgraph. You should use dateTime instead.
• Change of syntax for querying by id.

# Before
{
  me(id: [0x1, 0x2]) {
    ...
  }
}

# Now
{
  me(func: uid(0x1, 0x2)) {
    ...
  }
}

• Dgraph doesn’t fingerprint xids anymore. They are now treated similarly to other edges. So now if you had an xid and you wanted to query by it you would use.

# You need to have an index on xid for calling `eq` function.
{
  me(func: eq(xid, "alice")) {
    ....
  } 
}

• /admin/backup is now /admin/export. It outputs blank nodes which can now be used to load data into a fresh instance.
• There is a separate port for http (default 8080) and grpc (default 9080) now.

Bugfixes

• Remove concurrent filtering data race. Issue #1020
• Fix panic issues related to tracing. Wait for all goroutines to finish before retuning error.
• Fix crash caused by nil list. #1035

TODO(pawan) - Change links for docs to point to v0.8 and add all bugfixes.

[yupengfei (于鹏飞)]

Thank you for you great work.