Memgraph v3.12.0

pages/fundamentals/data-durability.mdx

@@ -95,6 +95,39 @@ via `--storage-snapshot-retention-count`.
 enforces periodic snapshots when WAL is enabled and will fail to start if WAL is
 enabled with snapshot interval set to zero.
 
+<h4 className="custom-header">WAL data integrity</h4>
+
+<Callout type="info">
+Per-transaction WAL checksums were introduced in Memgraph v3.12.
+
+WAL files written by older versions do not contain checksums and are recovered
+without integrity verification. Checksum verification applies only to WAL files
+written by Memgraph v3.12 or newer.
+</Callout>
+
+To guard against silent on-disk corruption, Memgraph protects WAL files with
+[CRC32](https://en.wikipedia.org/wiki/Cyclic_redundancy_check) checksums:
+
+- The **WAL file header** (offsets and metadata such as the UUID, epoch ID and
+  sequence number) is protected by its own checksum.
+- **Each transaction** is protected by a 4-byte checksum covering the
+  transaction's bytes (transaction start, deltas and transaction end).
+
+Checksums are verified automatically during recovery. If a transaction's stored
+checksum does not match the recomputed value, the WAL is considered corrupted at
+that point and recovery stops, so corrupted data is never applied to the
+database. A mismatch in the WAL header causes recovery from that file to fail.
+
+The same checksums protect WAL files that are buffered on disk on a replica
+before being applied, so corruption introduced between the main and the replica
+is detected before the data is committed. Deltas streamed during the commit
+(`PrepareCommitRpc`) are not checksummed because the TCP transport already
+provides integrity guarantees.
+
+<Callout type="info">
+Snapshots are not yet protected by checksums.
+</Callout>
+
 ### Snapshots
 Snapshots provide a faster way to restore the states of your database. Snapshots
 are created periodically based on the value defined with the

pages/querying/functions.mdx

@@ -182,7 +182,7 @@ All aggregation functions can be used with the `DISTINCT` operator to perform ca
 | `endsWith`   | `endsWith(string: string, substring: string) -> (boolean)`                               | Check if the first argument ends with the second.                                                                                        |
 | `left`       | `left(string: string, count: integer) -> (string)`                                       | Returns a string containing the specified number of leftmost characters of the original string.                                          |
 | `lTrim`      | `lTrim(string: string) -> (string)`                                                      | Returns the original string with leading whitespace removed.                                                                             |
-| `replace`    | `replace(string: string, search-string: string, replacement-string: string) -> (string)` | Returns a string in which all occurrences of a specified string in the original string have been replaced by another (specified) string. |
+| `replace`    | `replace(string: string, search-string: string, replacement-string: string) -> (string)` | Returns a string in which all occurrences of a specified string in the original string have been replaced by another (specified) string. An empty `search-string` matches at every position. |
 | `reverse`    | `reverse(string: string) -> (string)`                                                    | Returns a string in which the order of all characters in the original string have been reversed.                                         |
 | `right`      | `right(string: string, count: integer) -> (string)`                                      | Returns a string containing the specified number of rightmost characters of the original string.                                         |
 | `rTrim`      | `rTrim(string: string) -> (string)`                                                      | Returns the original string with trailing whitespace removed.                                                                            |

pages/release-notes.mdx

@@ -46,6 +46,42 @@ guide.
 
 ## 🚀 Latest release
 
+### Memgraph v3.12.0 - July 29th, 2026
+
+{<h4 className="custom-header">✨ New features</h4>}
+
+- Added `--storage-light-edge` (default `false`) to opt into a compact light-edge
+  storage path for lower memory use on edge-heavy graphs. The flag must be enabled
+  at startup; when off, behavior is unchanged.
+  [#4228](https://github.com/memgraph/memgraph/pull/4228)
+- Light-edge storage (with `--storage-light-edge`) uses a dedicated edge pool and
+  graveyard reclamation for create, find, and delete, reducing per-edge memory
+  overhead while keeping transactional semantics.
+  [#4271](https://github.com/memgraph/memgraph/pull/4271)
+
+{<h4 className="custom-header">🛠️ Improvements</h4>}
+
+- WAL files are now protected with CRC32 checksums. The WAL header and each
+  transaction carry their own checksum, which is verified during recovery and on
+  replicas before the data is applied, so silent on-disk corruption is detected
+  instead of being recovered. WAL files written by older versions remain
+  recoverable without verification.
+  [#4225](https://github.com/memgraph/memgraph/pull/4225)
+
+{<h4 className="custom-header">🐞 Bug fixes</h4>}
+
+- Fixed `replace()` causing an infinite loop and OOM when the search string is empty. Empty search now inserts the replacement at every character boundary with bounded allocation, so queries such as `replace("abc", "", "-")` return `"-a-b-c-"` instead of crashing the server. [#4269](https://github.com/memgraph/memgraph/pull/4269)
+- Fixed Bolt 4.4 clients receiving routing tables from data instances and
+  incorrectly defaulting the target database. Data instances now reject routing
+  requests, and database selection over Bolt 4.4 works as expected.
+  [#4270](https://github.com/memgraph/memgraph/pull/4270)
+
+### Lab v3.12.0 - July 29th, 2026
+
+<LabReleasesClient version="3.12.0" />
+
+## Previous releases
+
 ### Memgraph v3.11.0 - June 17th, 2026
 
 {<h4 className="custom-header">⚠️ Breaking changes</h4>}
@@ -320,8 +356,6 @@ guide.
 
 <LabReleasesClient version="3.11.0" />
 
-## Previous releases
-
 ### Memgraph v3.10.1 - May 15th, 2026
 
 {<h4 className="custom-header">🐞 Bug fixes</h4>}