1.39.1

Merged PRs

dolt

• 7901: Zachmu/schemas2 merge
• 7899: Properly add database collation change when using -a option in dolt commit
  This PR fixes a case where we don't properly handle database collation changes with the -a option in dolt commit.
  fixes #7897
• 7888: [sort] index build streams sorted edits
  Use sorting to skip more steps building a prolly map. Shaves maybe 20-25% off of external index rebuilds.
  This also fixes a bug where we were incorrectly using only the prefix descriptor to sort secondary index keys.

go-mysql-server

• 2512: Spooling shortcut for one/zero return schemas
  Nodes that return zero or one row don't need a beefy channel/wait group setup to execute. They just need to grab the first row and close the iterator. There are several nodes that incorrectly reported their schemas previously, which I've updated to be more accurate. There are some nodes that optionally return rows, which I've simplified to return an empty schema that can be differentiated from the nil schema. We could make the distinction more explicit, also.
  bump with perf here: #7894

vitess

• 348: Allowing caching plugin to be specified in string quotes
  The CREATE USER ... IDENTIFIED WITH syntax (MySQL ref) allows the caching plugin to be specified in string quotes, but our parser only supported identifier quotes.
  This came up as part of binlog replication testing – MySQL was sending a CREATE USER statement from the primary to a Dolt replica, but Dolt wasn't able to parse the statement because of the use of string quotes around the caching plugin name.
• 347: Added InjectedStatement
  This is the same as InjectedExpr, except for statements instead of expressions.

Closed Issues

• 7891: filter-branch destroys working and staged roots
• 7897: Pomelo Entity Framework connector is not able to commit changes
• 7890: Pomelo Entity Framework connector is not able to recreate database.

1.39.0

Merged PRs

dolt

• 7895: prevent filter-branch when there are local changes
  This PR changes filter-branch to detect any local changes so working/staged changes aren't lost.
  A future PR should include changes to have the working set just be applied over the result of dolt filter-branch.
  partially addresses: #7891

go-mysql-server

• 2512: Spooling shortcut for one/zero return schemas
  Nodes that return zero or one row don't need a beefy channel/wait group setup to execute. They just need to grab the first row and close the iterator. There are several nodes that incorrectly reported their schemas previously, which I've updated to be more accurate. There are some nodes that optionally return rows, which I've simplified to return an empty schema that can be differentiated from the nil schema. We could make the distinction more explicit, also.
  bump with perf here: #7894
• 2511: Adding mapping to error code 1049 for ErrDatabaseNotFound errors
  When a database doesn't exist, MySQL returns error code 1049. This change adds a mapping to error code 1049 for ErrDatabaseNotFound errors, and updates our handler so that ComInitDB messages will map errors to MySQL error codes.
  This is needed because tooling (e.g. Pomelo EntityFramework MySQL library) can rely on this error code in application logic.
  Related to #7890

Closed Issues

• 7890: Pomelo Entity Framework connector is not able to recreate database.

1.38.3

Merged PRs

dolt

• 7884: [tree] return blob builders to pool after use
  I added a builder pool and never returned the objects, this adds the Put().
• 7882: Bug fix: no-op dolt_pull() was leaving working set dirty
  Customer-reported bug. Two dolt_pull() operations on two branches in the same session when local branches are already up to date, with @@autocommit off, leave the session unable to commit because two branch heads are considered dirty. See new bats test for details on reproducing.
  The issue is that DoltSession.SetWorkingSet() marks that branch head dirty until the transaction is committed. Most merge code paths used by pull involve performing a dolt_commit(), which has the side effect of zeroing out the current transaction, meaning the next statement would get a new transaction and fresh working sets loaded from disk, avoiding the dirty state problem. Only the code path where the branch head is already up to date is affected by this bug. All the merge library code that actually needs to call DoltSession.SetWorkingSet() (only necessary before a dolt_commit happens, or in the case of a squash where changes should remain in the working set) already does so, making the additional call in dolt_pull.go redundant and leading to this buggy behavior in the no-change case.
  There are probably still related bugs for session state management during pull and merge operations, but I want to keep this fix narrow to address the customer issue while I build up more robust (non-bats) tests for pull.
• 7878: Move sql patch statement generation APIs to the sqlfmt package
  We have a few different APIs scattered around for generating SQL patch statements. I needed to make some functions from dolt_patch_table_function.go public to generate DDL statements for binlog support, so I moved them into the sqlfmt package and cleaned up some package import cycles along the way.
• 7872: Various test utils and small fixes
  As part of the work for binlog source support (on fulghum/binlog_prototype branch), these are various smaller changes to tidy up docs, packaging, small bug fixes, and add new test utils that I've pulled out into this PR to review separately.
  Notable changes:
  • Adds the third version component to the go version in our go.mod. Two component versions indicate a development version, not a release version and cause an error about not being able to download a toolchain.
  • Allows Dolt binlog replicas to accept the SOURCE_AUTO_POSITION config parameter, and errors if a user attempts to disable GTID auto positioning.
  • Adds several new test util functions specific to binlog testing.
• 7870: go/utils/publishrelease: Bump MUSL toolchains used for cutting releases.
  The new toolchain uses MUSL + mimalloc.
  Include the mimalloc license in our released LICENSES notice.
• 7859: Cache table and schema indexes on schema address
  The bulk of ~1ms read and write TPC-C queries benefit from caching table and index schemas, which have a lifecycle between schema migrations/alter statements/new table additions. This is in contrast to how we've typically cached objects using the root value hash, which is great for read-only workflows, but has a much shorter half-life.

go-mysql-server

• 2511: Adding mapping to error code 1049 for ErrDatabaseNotFound errors
  When a database doesn't exist, MySQL returns error code 1049. This change adds a mapping to error code 1049 for ErrDatabaseNotFound errors, and updates our handler so that ComInitDB messages will map errors to MySQL error codes.
  This is needed because tooling (e.g. Pomelo EntityFramework MySQL library) can rely on this error code in application logic.
  Related to #7890
• 2510: Fix race errors with memory tables
  We use this library for running our tests. These are run with the -race flag - and we are seeing some errors related to concurrency and updating of the tables map.
  I've added a sync.Mutex to all the places where this map is updated - our tests are now passing :)
• 2504: Added InjectedStatement as an AST node
  This is the same as InjectedExpr, except for statements instead of expressions.
• 2502: Use Uint32 for SEQ_IN_INDEX in 'SHOW INDEXES' queries.
  This is seemingly the correct type for this field.
  MySQL Connector/NET expects this for servers >8.0.1: https://github.com/mysql/mysql-connector-net/blob/8.4.0/MySQL.Data/src/SchemaProvider.cs#L298-L300
  Fixes dolthub/go-mysql-server#2501

vitess

• 347: Added InjectedStatement
  This is the same as InjectedExpr, except for statements instead of expressions.
• 346: support DATE, TIME, and TIMESTAMP literal parsing
  The SQL standard has special syntax for parsing date, time, and timestring literals.
  https://dev.mysql.com/doc/refman/8.0/en/date-and-time-literals.html
  This PR adds support for that.
  Code was mostly taken from vitessio.
  The types are still left as string types, as type conversion later on handles it just fine.
• 345: parse type aliases in cast
  add support for statements like:
  • select cast(<str> as character)
  • select cast(<str> as double precision)
  • select cast(<str> as read)

Closed Issues

• 2501: Problems with MySQL Connector/NET (Mysql.Data) and go-mysql-server
• 2503: "ON UPDATE CURRENT_TIMESTAMP" not come into effect

1.38.2

Merged PRs

dolt

• 7880: Migrate dolt remote to SQL
  Fixes: #7622
• 7879: avoid NewEmptyIndex when table does not exist
  It would be better to have NewEmptyIndex not write to chunkstore, but I'm not sure if it's possible right now.
  Workaround is to just avoid calling it altogether in this particular case.

Closed Issues

• 7622: Migrate dolt remote to SQL

Performance

Read Tests	MySQL	Dolt	Multiple
covering_index_scan	2.07	3.02	1.5
groupby_scan	13.22	17.32	1.3
index_join	1.34	5.18	3.9
index_join_scan	1.27	2.18	1.7
index_scan	35.59	53.85	1.5
oltp_point_select	0.17	0.51	3.0
oltp_read_only	3.36	8.28	2.5
select_random_points	0.33	0.8	2.4
select_random_ranges	0.39	0.95	2.4
table_scan	35.59	55.82	1.6
types_table_scan	75.82	137.35	1.8
reads_mean_multiplier			2.1

Write Tests	MySQL	Dolt	Multiple
oltp_delete_insert	7.98	6.67	0.8
oltp_insert	3.75	3.25	0.9
oltp_read_write	8.43	15.83	1.9
oltp_update_index	3.82	3.49	0.9
oltp_update_non_index	3.82	3.43	0.9
oltp_write_only	5.37	7.56	1.4
types_delete_insert	7.7	7.56	1.0
writes_mean_multiplier			1.1

TPC-C TPS Tests	MySQL	Dolt	Multiple
tpcc-scale-factor-1	101.66	22.89	4.4
tpcc_tps_multiplier			4.4

Overall Mean Multiple	2.53

1.38.1

Merged PRs

dolt

• 7877: keep sql.Schema for conflicts table schema
  Previously, we would create a new schema of NomStringKind for every column. Now, we just reuse the underlying sql.Schema.
  #7874
• 7876: Improve error messages for CLI commands when a sql-server is running
  Related to #7873
  Resolves #7875
• 7866: update release process for new config refactor
• 7864: move config
• 7862: Bug fix: sql-server should initialize persisted global vars
  The local config store (.dolt/config.json) can store persisted global variable values, but when --data-dir is used when starting a sql-server, the local configuration doesn't get loaded properly.
• 7860: Bug fix: load local config when using --data-dir
  When using the --data-dir flag to work on a Dolt directory outside of the current working directory, the local configuration in the Dolt directory wasn't getting correctly loaded. This change evaluates the --data-dir parameter earlier, so that the first time we load the Dolt environment, we can pass the data directory and get the local configuration loaded correctly.
• 7858: [nbs] safer peek root hash record
• 7848: Added additional function to RootValue
  This just adds a function to the RootValue for special merge logic, which is used by Doltgres.
• 7846: [dsess] session trigger cache

go-mysql-server

• 2499: fix LIKE NULL edge case
  This PR fixes an edge case where SELECT <str> LIKE NULL should return NULL instead of false.
• 2497: trim whitespace when converting strings to numbers
  fixes #7854
• 2495: fix panic in VALUES constructor
  When the number of rows in a ... VALUES ROW(...), ROW(...) statement were not equal, we would throw a panic.
  This PR also unskips some tests that are now fixed.
  Companion PR: #6849
  fixes: #6849
• 2494: Replace count star also matches single column pk
• 2493: Implement status variables for Slow_queries, Max_used_connections, Com_select, and Connections
  Adds support for four new status variables:
  • Slow_queries
  • Max_used_connections
  • Com_select
  • Connections
    Note that Connections currently only reports the successful connection attempts, but MySQL includes all connection attempts in that status variable. To capture the failed attempts, we'll need to expose that information from the Vitess layer.
    Also removes a mutex that was covering the whole scope over all status variables. Now that each individual status variable has a value that uses an atomic instance, we don't need to synchronize at a larger scope.
    Related to #7646
• 2492: skip source values analyze when it only contains simple types

vitess

• 345: parse type aliases in cast
  add support for statements like:
  • select cast(<str> as character)
  • select cast(<str> as double precision)
  • select cast(<str> as read)
• 344: make row optional in VALUES constructor and insert statement
  This PR adds additional syntax support for VALUE constructor.
  fixes #6849
  fixes #7853
• 338: Add a schema qualifier to table names

Closed Issues

• 7873: Running sql-server from an empty state make inconsistent repository
• 7874: Failed to write conflicts table
• 7875: Confusing error messages when using Dolt CLI from within a running Dolt sql-server directory
• 7854: trim whitespace when casting from string
• 7853: make ROW keyword optional in VALUES statement
• 6849: support INSERT INTO ... (VALUES ROW(...)) statement
• 7845: Make sure deleting a branch behaves similarly to drop database

Performance

Read Tests	MySQL	Dolt	Multiple
covering_index_scan	2.07	3.02	1.5
groupby_scan	13.22	17.63	1.3
index_join	1.34	5.18	3.9
index_join_scan	1.27	2.22	1.7
index_scan	34.33	54.83	1.6
oltp_point_select	0.17	0.51	3.0
oltp_read_only	3.36	8.43	2.5
select_random_points	0.32	0.8	2.5
select_random_ranges	0.39	0.95	2.4
table_scan	34.33	55.82	1.6
types_table_scan	73.13	137.35	1.9
reads_mean_multiplier			2.2

Write Tests	MySQL	Dolt	Multiple
oltp_delete_insert	7.98	6.67	0.8
oltp_insert	3.75	3.25	0.9
oltp_read_write	8.28	15.83	1.9
oltp_update_index	3.82	3.49	0.9
oltp_update_non_index	3.82	3.43	0.9
oltp_write_only	5.28	7.56	1.4
types_delete_insert	7.56	7.56	1.0
writes_mean_multiplier			1.1

TPC-C TPS Tests	MySQL	Dolt	Multiple
tpcc-scale-factor-1	101.35	22.45	4.9
tpcc_tps_multiplier			4.9

Overall Mean Multiple	2.73

1.38.0

Merged PRs

This minor release includes a new entry in the dolt_status and dolt_diff system tables for database collation changes, making these tables backwards incompatible for some select statements. Changes to a dolt database collation will show up as table changes with the name __DATABASE__<db>. Additionally, tables starting with this prefix are not allowed.

dolt

• 7823: handle database charset/collation changes
  This PR makes dolt aware of database collation changes.
  We treat database collation changes similarly to a collation change to a table.
  To properly show a dolt diff we need to add support for show create database as of ..., which would require changes to vitess and gms. For now, we just show the new create statement.
  Addtionally, we should add support to resolve database collation merge conflicts.
  Affected functions are:
  • dolt add
  • dolt commit
  • dolt status
  • dolt diff
  • dolt merge
    Addresses: #7815
• 7819: use parser interface in engine
• 7803: Avoid escaping HTML characters when displaying them to the user.
  This fixes an issue where if a JSON document in the storage layer contains escaped characters, those escape sequences could end up being displayed to the user via the dolt sql -r json command.
• 7764: Bump golang.org/x/net from 0.17.0 to 0.23.0 in /go
  Bumps golang.org/x/net from 0.17.0 to 0.23.0.

go-mysql-server

• 2492: skip source values analyze when it only contains simple types
• 2491: ValidateInsertColumns avoids allocating hash map
• 2490: Avoid escaping HTML when Marshalling JSON
  Due to a misconfiguration, HTML characters were being escaped when marshaling JSON. This is unnecessary, and since we now potentially display marshalled JSON to the user, we shouldn't be doing this.
• 2488: System Variables: Add log_bin and change the default of performance_schema
  The log_bin system variable controls whether a MySQL server logs to the binary log or not.
  The performance_schema system variable was previously defaulted to 1, to match MySQL's default, but this can cause tools (e.g. Datadog) to believe that the performance_schema system tables are available, and then error out when trying to query them. Since we don't provide a performance_schema database, the new default for the performance_schema system variable is 0.
• 2487: Expand literals in comparisons when safe
• 2486: add parser interface in engine
  This PR creates sql.Parser interface. This interface is defined in the engine and it should be used rather than using mysql parser directly.
  Added GlobalParser variable to expose Doltgres parser for parsing view definition for now. It can also be used in places that needs doltgres-specific syntax parsing.

Closed Issues

• 7812: Entity Framework updating working set when there are no changes
• 7815: dolt workflows for manipulating the collation of a DB needed
• 6161: Optimizer statistics v1

1.37.0

The previous (now deleted) release 1.36.1 had a start up time issue for databases > 10GB. We patched it with this one. That release was only up for an hour or so, so it is unlikely anyone got it. Thus, we moved this to 1.37.0 to warn people, just in case.

This minor release includes an internal interface change to the chunk journal index. The first startup process for a database with the old index format will perform a rewrite. This rewrite is a one-time penalty that in testing is <5% of the time it would take to reimport the database.

Merged PRs

dolt

• 7833: Bug fix: Apply replication settings for newly cloned databases
  Dolt SQL servers using remote-based replication will pull new databases if the @@dolt_replication_remote_url_template system variable is configured, but those new databases weren't getting configured to continue pulling updates from the remote.
  This change registers the newly cloned databases as ReadReplicaDatabase instances, so that they will poll their remote and pull new commits. It also adds some additional logging to help debug issues with remote-based replication.
• 7829: Changed RootValue into an interface
  Companion:
  • dolthub/doltgresql#232
    This changes the RootValue into an interface. Every function that seems unique to Dolt's RootValue has been changed into a function variable, with the variable being overwritten from Doltgres to point to a different function.
• 7799: Archive Serialization and Deserialization
  This PR doesn't direclty change any Dolt behavior. It just lays the groundwork for archive creation and reading. Currently, no file is materialized by this code as unit tests exercise it with ByteSinks.
• 7780: Reformat journal index
  Change the way we write journal index lookups. Each write appends a lookup to a bufio.Writer that lazily writes to disk. And after some increment we flush a CRC/root value record for consistency checking the index during bootstrap. This avoids big stalls for flushing a batch of index records. We also only write an addr16 now, because that's what we load into the default chunk address map.
  Databases with the older format will pay a one-time startup penalty to rewrite the journal index. In testing this appears to be 5-10% of the import time for the database.
• 7836: Journal index offset 8bytes
  On >10GB datasets, offsets overflow uint32. Bug from previous PR #7780
• 7834: minver refactor to be used by doltgres
• 7821: Prevent panic when dropping columns in schema merge
  Fixes #7762
  In certain cases, performing a schema merge when the merged schema had fewer columns than the base schema would cause a panic.
  We actually had a test for this, but the test was disabled because a limitation in how the test harness generated column tags was causing incorrect detection of merge conflicts.
  To re-enable these tests, this PR slightly relaxes the logic for merge conflicts wrt column tags. This is safe to do because column tags shouldn't influence the result of merges outside of helping to identify renamed columns, so long as the merge behaves the same in both directions.

Closed Issues

• 7762: Panic during schema merge

Performance

Read Tests	MySQL	Dolt	Multiple
covering_index_scan	2.07	2.97	1.4
groupby_scan	13.22	17.63	1.3
index_join	1.37	5.18	3.8
index_join_scan	1.27	2.22	1.7
index_scan	34.33	53.85	1.6
oltp_point_select	0.17	0.51	3.0
oltp_read_only	3.36	8.43	2.5
select_random_points	0.33	0.8	2.4
select_random_ranges	0.39	0.95	2.4
table_scan	34.33	54.83	1.6
types_table_scan	74.46	134.9	1.8
reads_mean_multiplier			2.1

Write Tests	MySQL	Dolt	Multiple
oltp_delete_insert	7.98	6.91	0.9
oltp_insert	3.75	3.43	0.9
oltp_read_write	8.43	16.12	1.9
oltp_update_index	3.82	3.55	0.9
oltp_update_non_index	3.82	3.43	0.9
oltp_write_only	5.37	7.84	1.5
types_delete_insert	7.7	7.56	1.0
writes_mean_multiplier			1.1

TPC-C TPS Tests	MySQL	Dolt	Multiple
tpcc-scale-factor-1	102.12	22.29	4.6
tpcc_tps_multiplier			4.6

Overall Mean Multiple	2.60

1.36.0

This version does not include an interface change, but does include large changes to the performance and network utilization behavior of dolt fetch and related functionality, such as shallow clone and Dolt cluster replication.

Merged PRs

dolt

• 7828: Bug fix: Allow dolt init to use --data-dir param
  Previously, dolt init would use the value of --data-dir for almost all of the repository initialization, but the code that set up repository configuration would always use the current directory. This change allows callers to use dolt init with the --data-dir param to initialize directories other than the current working directory as Dolt repositories.
• 7825: Bug fix: Decimal type binlog serialization
• 7824: dolt fetch: Implement pipelined, continuous downloads during pulls from DoltHub and dolt sql-server remotes.
  Dolt fetch, pull, shallow clone and cluster replication will now make more aggressive utilization of available network resources.
• 7816: allow database alters and case insensitive check for info schema
  fixes: #7814

go-mysql-server

• 2488: System Variables: Add log_bin and change the default of performance_schema
  The log_bin system variable controls whether a MySQL server logs to the binary log or not.
  The performance_schema system variable was previously defaulted to 1, to match MySQL's default, but this can cause tools (e.g. Datadog) to believe that the performance_schema system tables are available, and then error out when trying to query them. Since we don't provide a performance_schema database, the new default for the performance_schema system variable is 0.
• 2485: Have LazyJSONDocument implement fmt.Stringer and driver.Valuer, in order to interoperate with other go SQL libraries.

Closed Issues

• 7814: dolt sql fails to run DDL operations
• 6624: Table size calculation using DATA_LENGTH in information schema is naive and massively overstates the size of tables

1.35.13

Merged PRs

dolt

• 7818: Apply a factor to better estimate information_schema.TABLES.DATA_LENGTH
information_schema.TABLES.DATA_LENGTH currently reports the max possible table size for a table, and doesn't take into account table file compression or that variable length fields (e.g. TEXT) are not always fully used. Tools such as DBeaver use this metadata to display table sizes, and since the estimates can easily be orders of magnitude greater than the actual size on disk, it can cause customers to be concerned by the reported sizes (e.g. #6624).
  As a short-term fix to make these estimates more accurate, we apply a constant factor to the max table size. I came up with this scaling factor by measuring a best case scenario (where no fields are variable length) and a worst case scenario (were all fields are variable length and only use a few bytes), then picking a value roughly in the middle. Longer-term, a better way to estimate table size on disk will be to use statistics data.
• 7810: fix output for dolt diff --stat -r json
  This PR tidys up the code for printing diffs, specifically for JSON result format, and prints --stat correctly for JSON result format.
  Additionally, we throw an error for SQL result format instead of just returning incorrect output. It might be worth implenting now, but I can just make an issue for it.
  fixes: #7800
• 7809: go/libraries/doltcore/sqle/dprocedures: dolt_pull.go: Improve CPU utilization of call dolt_pull.
• 7805: Fix: allow jsonSerializer to load JSON from LazyJSONDocument
• 7804: Changing database init/drop hooks to be a slice of hooks
  The Dolt database provider currently has a single init hook and a single drop hook. We have a few hooks, and in order to support multiple hooks, we chain them together. Binlog replication will also need to register a similar init and drop hook to capture database create/drop actions, so to prepare for that, this PR turns the single init hook and single drop hook into a slice of init hooks and a slice of drop hooks.
• 7802: adding --name-only option for dolt diff
  This PR adds support for --name-only option for dolt diff, which just prints the tables that have changed between the two commits. This mirrors git diff --name-only.
  fixes: #7797
• 7795: Serialization code for binlog events
  Provides support for serializing all Dolt data types into MySQL's binary encoding used in binlog events. Vitess provides good support for deserializing binary values from binlog events into Go datatypes, but doesn't provide any support for serializing types into MySQL's binary format. This PR pulls data out of Dolt's storage system and encodes it into MySQL's binary format. It would be interesting to split out the Dolt storage system specific code and the core MySQL serialization logic in the future, but this seems like the right first step.
  Related to #7512
• 7785: Use LazyJSONDocument when reading from a JSON column.
  This is the Dolt side of #7749
  The GMS PR is dolthub/go-mysql-server#2470
  LazyJSONDocument is an alternate implementation of sql.JSONWrapper that takes a string of serialized JSON and defers deserialization until it's actually required.
  This is useful because in the most common use case (selecting a JSON column), deserialization is never required.
  In an extreme example, I created a table with 8000 rows, with each row containing a 80KB JSON document.
  dolt sql -q "SELECT * FROM test_table" ran in 47 seconds using JSONDocument, and 28 seconds using LazyJSONDocument, nearly half the time.
  Even in cases where we do need to deserialize the JSON in order to filter on it, we can avoid reserializing it afterward, which is still a performance win.
  Of note: In some cases we use a special serializer (defined in json_encode.go::marshalToMySqlString) in order to produce a string that is, according to the docstring "compatible with MySQL's JSON output, including spaces."
  This currently gets used
  • In Query Diff
  • When hashing values for fulltext tables
  • When casting JSON columns to a text type
  • When writing values along the wire
    The last one is the most worrying, because it means that we can't avoid the serialization round-trip if we're connecting to a dolt server remotely. I discussed with Max whether or not we consider it a requirement to match MySQL's wire responses exactly for JSON, and agreed that we could probably relax that requirement. Casting a document to a text type will still result in the same output as MySQL.
• 7754: Index rebuilds with external key sorting
  Index builds now write keys to intermediate files and merge sort before materializing the prolly tree for the secondary index. This contrasts the default approach, which rebuilds the prolly tree each time we flush keys from memory. The old approach reads most of the tree with random reads and writes when memory flushes are unsorted keys. The new approach structures work for sequential IO by flushing sorted runs that become incrementally merge sorted. The sequential IO is dramatically faster for disk-based systems.

go-mysql-server

• 2485: Have LazyJSONDocument implement fmt.Stringer and driver.Valuer, in order to interoperate with other go SQL libraries.
• 2470: Add LazyJSONDocument, which wraps a JSON string and only deserializes it if needed.
  This is the GMS side of #7749
  This is a new JSONWrapper implementation. It isn't used by the GMS in-memory storage, but it will be used in Dolt to speed up SELECT queries that don't care about the structure of the JSON.
  A big difference between this and JSONDocument is that even after it de-serializes the JSON into a go value, it continues to keep the string in memory. This is good in cases where we would want to re-serialize the JSON later without changing it. (So statements like SELECT json FROM table WHERE json->>"$.key" = "foo"; will still be faster.) But with the downside of using more memory than JSONDocument)
• 2469: refactor index validation and prevent indexes over json columns
  This PR consolidates the logic to validate if an index.
  Additionally, it fixes a bug where create table t (i int, index (i, i)); was allowed.
  fixes: #6064
• 2466: Schema-qualified table names
  This PR also fixes a couple unrelated issues:
  • IMDB query plans are brought up to date (this is most of the change lines)
  • Fixed bugs in certain show statements (information_schema tests)

Closed Issues

• 7813: Ability to export diffs as SQL
• 6624: Table size calculation using DATA_LENGTH in information schema is naive and massively overstates the size of tables
• 7800: dolt diff --stat -r json produces invalid JSON
• 7749: Dolt serializes and deserializes JSON unnecessarily.
• 7797: dolt diff ... that only shows the tables changed in a simpler format

Performance

Read Tests	MySQL	Dolt	Multiple
covering_index_scan	2.14	3.13	1.5
groupby_scan	13.46	17.95	1.3
index_join	1.37	5.28	3.9
index_join_scan	1.27	2.26	1.8
index_scan	34.33	54.83	1.6
oltp_point_select	0.17	0.51	3.0
oltp_read_only	3.43	8.43	2.5
select_random_points	0.33	0.8	2.4
select_random_ranges	0.39	0.97	2.5
table_scan	34.33	54.83	1.6
types_table_scan	74.46	137.35	1.8
reads_mean_multiplier			2.2

Write Tests	MySQL	Dolt	Multiple
oltp_delete_insert	7.98	6.91	0.9
oltp_insert	3.75	3.43	0.9
oltp_read_write	8.43	16.41	1.9
oltp_update_index	3.82	3.55	0.9
oltp_update_non_index	3.82	3.49	0.9
oltp_write_only	5.37	7.98	1.5
types_delete_insert	7.7	7.56	1.0
writes_mean_multiplier			1.1

TPC-C TPS Tests	MySQL	Dolt	Multiple
tpcc-scale-factor-1	101.88	22.32	4.9
tpcc_tps_multiplier			4.9

Overall Mean Multiple	2.73

1.35.12

Merged PRs

dolt

• 7792: Fix nil write session panic
• 7790: chore: fix some function names
• 7776: dolt_history tables: Issue a warning when types have changed
  Adding a session warning when dolt_history tables can't create a rowConverter for a row due to a field's type having changed. In these cases, the old value can't always be returned safely as the new type, so we return NULL and issue a session warning. In the future, we could attempt to convert the old value to the new type.
  Follow up to #7771
• 7766: chore: use errors.New to replace fmt.Errorf with no parameters
• 7760: Support for multiple schemas in a database
  Companion PRs:
  dolthub/vitess#338
  dolthub/go-mysql-server#2466
  dolthub/doltgresql#181
  This PR is a proof of concept for addressing multiple table namespaces (schemas) in a database. This is to support schemas in Doltgres initially, but could also be used to implement storing multiple databases in the same Dolt commit graph if we wanted to do that. All tables are stored in the root's table map like always, but tables with non-empty schemas have that schema name prepended in its map key, surrounded by null bytes.
  There are lots of things that don't work yet. This is what does work:

  create schema mySchema;
  create schema otherSchema;
  CREATE TABLE mySchema.test (pk BIGINT PRIMARY KEY, v1 BIGINT);
  insert into mySchema.test values (1,1), (2,2);
  CREATE TABLE otherSchema.test (pk BIGINT PRIMARY KEY, v1 BIGINT);
  insert into otherSchema.test values (3,3), (4,4);
  SELECT * FROM mySchema.test;
  SELECT * FROM otherSchema.test;

  Things I specifically want feedback on:
  • I am not crazy about the sweeping changes to table-access interfaces in root_val.go. In particular it seems likely to cause errors over time as people forget to include schema names in code changes where necessary, silently breaking doltgres. Another option I considered was to introduce some sort of RootReader interface on top of root value, which you create with a particular schema name, and thereafter all table accesses reference the given schema. There may be places where we have to juggle multiple RootReader instances at once, rather than just asking for qualified table names from a single root. But this is the pattern I used for the boundary between GMS and Dolt and it worked well, so maybe it could work for root_val.go as well.

go-mysql-server

• 2482: don't check schema compatibility for select into

  fixes: #7781

• 2481: aliasExpr inputExpression case-insensitive check
  This PR adds case-insensitive check for aliasExpr.InputExpression and expr.String() to determine the expr is referencable.

• 2473: remove re-parsing select stmt in create view stmt
  Depends on dolthub/vitess#339

• 2466: Schema-qualified table names
  This PR also fixes a couple unrelated issues:

  • IMDB query plans are brought up to date (this is most of the change lines)
  • Fixed bugs in certain show statements (information_schema tests)

vitess

• 343: Exposing binary JSON encoding to SQL expression logic for testing
  Exposing logic in Vitess that decodes MySQL's internal, binary JSON serialization encoding, so that we can use it to test JSON serialization.
• 342: refactor and fully implement alter table syntax
  MySQL Docs; https://dev.mysql.com/doc/refman/8.0/en/alter-table.html
  fixes: dolthub/go-mysql-server#2472
• 340: improving partition parsing
  partially addresses: dolthub/go-mysql-server#2472
• 339: capture select expressions that are sub statements within other expressions
• 338: Add a schema qualifier to table names

Closed Issues

• 6064: Prevent Indexing JSON Fields
• 7781: cannot convert type longtext COLLATE utf8mb4_0900_ai_ci to datetime
• 2472: Parser support for PARTITION BY

Performance

Read Tests	MySQL	Dolt	Multiple
covering_index_scan	2.07	3.02	1.5
groupby_scan	13.7	17.63	1.3
index_join	1.34	5.18	3.9
index_join_scan	1.27	2.26	1.8
index_scan	34.33	52.89	1.5
oltp_point_select	0.17	0.51	3.0
oltp_read_only	3.36	8.43	2.5
select_random_points	0.33	0.8	2.4
select_random_ranges	0.39	0.95	2.4
table_scan	34.33	53.85	1.6
types_table_scan	74.46	158.63	2.1
reads_mean_multiplier			2.2

Write Tests	MySQL	Dolt	Multiple
oltp_delete_insert	7.98	6.91	0.9
oltp_insert	3.75	3.43	0.9
oltp_read_write	8.43	16.12	1.9
oltp_update_index	3.82	3.55	0.9
oltp_update_non_index	3.82	3.43	0.9
oltp_write_only	5.37	7.98	1.5
types_delete_insert	7.7	7.56	1.0
writes_mean_multiplier			1.1

TPC-C TPS Tests	MySQL	Dolt	Multiple
tpcc-scale-factor-1	101.61	4.98	4.2
tpcc_tps_multiplier			4.2

Overall Mean Multiple	2.50