@@ -159,7 +159,7 @@ ORDER BY time DESC
 LIMIT 30;
 ```
 
-Many connections in `Sleep` with large `time` values point to leaks or oversized pools. Many connections in `Query` with a state such as `Waiting for table metadata lock` or long-running statements point to a blocking problem: one slow statement or lock holder is making everything else wait, and each waiting request keeps its connection. To track down row lock waits, see [MySQL Lock Wait Timeout Exceeded](/resources/blog/mysql-lock-wait-timeout-exceeded).
+Many connections in `Sleep` with large `time` values point to leaks or oversized pools. Many connections in `Query` with a state such as `Waiting for table metadata lock` or long-running statements point to a blocking problem: one slow statement or lock holder is making everything else wait, and each waiting request keeps its connection. To track down row lock waits, see [MySQL Lock Wait Timeout Exceeded](/blog/mysql-lock-wait-timeout-exceeded).
 
 ## Step 3: Relieve the Immediate Pressure
 
@@ -197,7 +197,7 @@ The default `wait_timeout` is 28800 seconds (8 hours). A leaked connection can s
 SET GLOBAL wait_timeout = 600;
 ```
 
-The new value applies to connections opened afterwards. Make sure every connection pool retires its connections before this timeout, otherwise the pool will hand out connections the server has already closed. Since MySQL 8.0.24, clients then receive `ERROR 4031 (HY000): The client was disconnected by the server because of inactivity`, and older drivers report a lost connection. If you see that after changing the timeout, see [MySQL Error 2013: Lost Connection During Query](/resources/blog/mysql-error-2013-lost-connection).
+The new value applies to connections opened afterwards. Make sure every connection pool retires its connections before this timeout, otherwise the pool will hand out connections the server has already closed. Since MySQL 8.0.24, clients then receive `ERROR 4031 (HY000): The client was disconnected by the server because of inactivity`, and older drivers report a lost connection. If you see that after changing the timeout, see [MySQL Error 2013: Lost Connection During Query](/blog/mysql-error-2013-lost-connection).
 
 ## Step 4: Fix the Cause
 
@@ -279,7 +279,7 @@ This worst case is rarely reached, but if it is far beyond the RAM of the host,
 
 ### Useful Concurrency
 
-A database can only run as many queries in parallel as it has CPU cores and I/O capacity. Past that point, extra concurrent queries just queue inside the server. That is why well-tuned pools are usually small: a common starting heuristic, popularized by the HikariCP documentation, is about twice the number of CPU cores of the database server, then adjusted by measurement. Use the [connection pool size calculator](https://chat2db.ai/tools/connection-pool-size-calculator) to work out a per-instance pool size from your core count, instance count, and headroom, and see the [HikariCP connection pool size guide](/resources/blog/hikaricp-connection-pool-size-guide) for the reasoning behind the numbers.
+A database can only run as many queries in parallel as it has CPU cores and I/O capacity. Past that point, extra concurrent queries just queue inside the server. That is why well-tuned pools are usually small: a common starting heuristic, popularized by the HikariCP documentation, is about twice the number of CPU cores of the database server, then adjusted by measurement. Use the [connection pool size calculator](https://chat2db.ai/tools/connection-pool-size-calculator) to work out a per-instance pool size from your core count, instance count, and headroom, and see the [HikariCP connection pool size guide](/blog/hikaricp-connection-pool-size-guide) for the reasoning behind the numbers.
 
 ### File Descriptor Limits
 
@@ -307,7 +307,7 @@ If you use MySQL Shell or connectors over the X Protocol (port 33060), those con
 
 A GUI helps a lot during step 4, when you want to sort and filter a few hundred processlist rows quickly. In [Chat2DB](https://app.chat2db.ai/) you can run the grouping queries above, sort the result grid by any column, and save the diagnostic queries for the next incident. For other connection errors you encounter, like 1203, 1226, or 1227, the free [MySQL error code lookup tool](https://chat2db.ai/tools/mysql-error-code-lookup) explains each code.
 
-If you also run PostgreSQL, its equivalent error is covered in [PostgreSQL Too Many Clients Already](/resources/blog/postgres-too-many-clients-already-fix).
+If you also run PostgreSQL, its equivalent error is covered in [PostgreSQL Too Many Clients Already](/blog/postgres-too-many-clients-already-fix).
 
 ## FAQ
 
 
@@ -499,7 +499,7 @@ When a 1054 is not obvious, work through this list in order:
 
 Keeping the table structure visible next to the editor removes most of this guesswork. In [Chat2DB](https://chat2db.ai/download), autocomplete suggests real column names for each alias as you type, so misspelled or out-of-scope columns stand out before you run the query. For other error numbers you run into along the way, such as 1356 or 1146, you can look them up with the free [MySQL error code lookup tool](https://chat2db.ai/tools/mysql-error-code-lookup).
 
-Related guides in this series: [MySQL Error 1064: You Have an Error in SQL Syntax](/resources/blog/mysql-error-1064-syntax-error) for parser errors, and [MySQL Error 1055: Fix only_full_group_by](/resources/blog/mysql-error-1055-only-full-group-by) for `GROUP BY` problems that often appear right after fixing a 1054.
+Related guides in this series: [MySQL Error 1064: You Have an Error in SQL Syntax](/blog/mysql-error-1064-syntax-error) for parser errors, and [MySQL Error 1055: Fix only_full_group_by](/blog/mysql-error-1055-only-full-group-by) for `GROUP BY` problems that often appear right after fixing a 1054.
 
 ## FAQ
 
 
@@ -216,7 +216,7 @@ WHERE rn = 1;
 +-------------+----------+----------+--------+---------------------+
 ```
 
-The `id DESC` tie-breaker makes the result deterministic when two orders share a timestamp. Use `RANK()` instead of `ROW_NUMBER()` if you want all tied rows. Window functions are covered in more depth in [MySQL Window Functions](/resources/blog/mysql-window-functions).
+The `id DESC` tie-breaker makes the result deterministic when two orders share a timestamp. Use `RANK()` instead of `ROW_NUMBER()` if you want all tied rows. Window functions are covered in more depth in [MySQL Window Functions](/blog/mysql-window-functions).
 
 On MySQL 5.7, which has no window functions, join back to the aggregated keys:
 
 
@@ -18,7 +18,7 @@ import Authors, { Author } from "components/authors";
 
 The immediate fix is usually obvious once you know which key was hit and which value collided. The harder cases are the ones where the "duplicate" does not look like a duplicate: a collation that treats `é` as `e`, an `AUTO_INCREMENT` column that ran out of range, or a replica that diverged from its source. This guide covers all of them on MySQL 8.0 and 8.4.
 
-If you work with PostgreSQL as well, the equivalent error there is covered in [duplicate key value violates unique constraint](/resources/blog/postgres-duplicate-key-value-violates-unique-constraint).
+If you work with PostgreSQL as well, the equivalent error there is covered in [duplicate key value violates unique constraint](/blog/postgres-duplicate-key-value-violates-unique-constraint).
 
 ## Reproducing MySQL Error 1062
 
 
@@ -262,7 +262,7 @@ CREATE USER 'app'@'%' IDENTIFIED BY 'secret';
 GRANT SELECT ON demo.* TO 'app'@'%';
 ```
 
-Likewise, the `PASSWORD()` function is gone. `SELECT PASSWORD('x');` fails near `('x')`. Use `ALTER USER ... IDENTIFIED BY` to change passwords. If password problems follow the upgrade, see [MySQL Error 1045: Access Denied](/resources/blog/mysql-error-1045).
+Likewise, the `PASSWORD()` function is gone. `SELECT PASSWORD('x');` fails near `('x')`. Use `ALTER USER ... IDENTIFIED BY` to change passwords. If password problems follow the upgrade, see [MySQL Error 1045: Access Denied](/blog/mysql-error-1045).
 
 ## Cause 5: Syntax From Another SQL Dialect
 
@@ -347,7 +347,7 @@ WHERE id IN (
 );
 ```
 
-The extra derived table is needed because MySQL does not allow `LIMIT` directly inside an `IN` subquery. Batching like this also keeps locks short; if large updates are timing out, see [MySQL Lock Wait Timeout Exceeded](/resources/blog/mysql-lock-wait-timeout-exceeded).
+The extra derived table is needed because MySQL does not allow `LIMIT` directly inside an `IN` subquery. Batching like this also keeps locks short; if large updates are timing out, see [MySQL Lock Wait Timeout Exceeded](/blog/mysql-lock-wait-timeout-exceeded).
 
 ## Cause 6: Stored Programs Without DELIMITER
 
 
@@ -200,13 +200,13 @@ INSERT INTO u9 VALUES
 ERROR 1062 (23000): Duplicate entry 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' for key 'u9.url'
 ```
 
-That is a false duplicate. If you need true uniqueness on a long value, use a hash column (Fix 4). For more on this error, see [MySQL Error 1062: Duplicate Entry](/resources/blog/mysql-error-1062-duplicate-entry).
+That is a false duplicate. If you need true uniqueness on a long value, use a hash column (Fix 4). For more on this error, see [MySQL Error 1062: Duplicate Entry](/blog/mysql-error-1062-duplicate-entry).
 
 Other prefix index limitations:
 
 - They cannot be used as covering indexes, because the index does not contain the full value.
 - They cannot satisfy `ORDER BY url` or `GROUP BY url` on their own.
-- A foreign key cannot reference a prefix-indexed column. For related errors see [MySQL Error 1452](/resources/blog/mysql-error-1452-foreign-key-constraint-fails).
+- A foreign key cannot reference a prefix-indexed column. For related errors see [MySQL Error 1452](/blog/mysql-error-1452-foreign-key-constraint-fails).
 - `TEXT` and `BLOB` columns can only be indexed with a prefix. Without one you get `ERROR 1170 (42000): BLOB/TEXT column 'url' used in key specification without a key length`.
 
 ### Watch Out for Non-Strict Mode
 
@@ -316,7 +316,7 @@ DELIMITER ;
 CALL purge_sessions('2026-09-01 00:00:00', 10000);
 ```
 
-The same batching applies to bulk `UPDATE`s. When child tables reference the rows you delete, make sure the foreign key has `ON DELETE CASCADE` or delete children first; otherwise the batches fail with the errors described in [MySQL Error 1452: Foreign Key Constraint Fails](/resources/blog/mysql-error-1452-foreign-key-constraint-fails).
+The same batching applies to bulk `UPDATE`s. When child tables reference the rows you delete, make sure the foreign key has `ON DELETE CASCADE` or delete children first; otherwise the batches fail with the errors described in [MySQL Error 1452: Foreign Key Constraint Fails](/blog/mysql-error-1452-foreign-key-constraint-fails).
 
 If you prefer to run maintenance statements from a GUI, [Chat2DB](https://chat2db.ai/download) shows the affected row count for every statement and lets you keep a transaction open while you check it, which pairs well with batch deletes.
 
@@ -326,7 +326,7 @@ MariaDB supports the same `sql_safe_updates` variable, the same error 1175, and
 
 ## When the error number is different
 
-Safe update mode only produces error 1175 (and error 1104 from `max_join_size` in client sessions started with `--safe-updates`). If your `UPDATE` fails with another code, such as a duplicate key error or an access denied error, see [MySQL Error 1062](/resources/blog/mysql-error-1062-duplicate-entry) or [MySQL Error 1045](/resources/blog/mysql-error-1045). You can also look up any MySQL error number and its meaning with the free [MySQL error code lookup tool](https://chat2db.ai/tools/mysql-error-code-lookup).
+Safe update mode only produces error 1175 (and error 1104 from `max_join_size` in client sessions started with `--safe-updates`). If your `UPDATE` fails with another code, such as a duplicate key error or an access denied error, see [MySQL Error 1062](/blog/mysql-error-1062-duplicate-entry) or [MySQL Error 1045](/blog/mysql-error-1045). You can also look up any MySQL error number and its meaning with the free [MySQL error code lookup tool](https://chat2db.ai/tools/mysql-error-code-lookup).
 
 ## FAQ