Database Articles

SQL Server 2016 Patch has broken SQL Server - need traceflag 902 to access server

<p>Our platforms team has changed the way in which we install SQL Server patches.</p> <p>This weekend, a number of patches have been applied on SQL Server 2016 and appear to have broken the servers.</p> <pre><code>Database 'master' is upgrading script 'msdb110_upgrade.sql' from level 218110212 to level 218110293 </code></pre> <p>As a temporary fix, we have managed to get the servers back using traceflag 902.</p> <p>During the patch, the following file is run: <code>msdb110_upgrade.s

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Windows: DolphinDB aggregation query throws "Can't open file" error even though partition files exist; simple queries work fine

<p>I’m running DolphinDB (Windows version) and encountering a file access error only during aggregation queries with GROUP BY / HAVING, while simple filter queries run without issues.</p> <p>Scenario 1.Simple query (no error):</p> <pre><code>select * from loadTable(&quot;dfs://citi_data&quot;, &quot;factor_data&quot;) where code = &quot;000001.SZ&quot; </code></pre> <p>2.Aggregation query (throws error for certain code values):</p> <pre><code>select count(*) as cnt from loadTable(&

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What happens when an automatic statistics update fails during synchronous query plan compilation?

<p>It is certainly documented that an automatic statistics update can fail. The documentation for the <a href="https://learn.microsoft.com/en-us/sql/relational-databases/event-classes/auto-stats-event-class?view=sql-server-ver17" rel="nofollow noreferrer">Auto Stats Event Class</a> mentions this many times. But when this happens, what happens to the compilation of the query that was trying to synchronously compile a plan?</p> <p>My suspicion is that if anything in the plan compilati

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What availability group information is unique to sys.dm_os_ring_buffers?

<p><code>sys.dm_os_ring_buffers</code> <a href="https://learn.microsoft.com/en-us/sql/database-engine/availability-groups/windows/always-on-ring-buffers?view=sql-server-ver17" rel="nofollow noreferrer">contains information about availability groups</a>. I have read a tremendous amount online about debugging availability groups, but I have never seen anyone use or even suggest using <code>sys.dm_os_ring_buffers</code> to debug an availability group issue.</p> <p>This gives me two que

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We caught a slow SQL Server query way too late. How do teams usually investigate this?

This keeps happening and it’s getting old. A query works fine in dev and staging. Then it hits production traffic, starts timing out, and suddenly everyone is pretending the dashboard didn’t just catch fire. We’re looking into dbForge Studio for SQL Server to analyze execution plans and profile queries. It looks useful, but I’m trying to understand how teams actually fit this into their workflow. Do you use tools like this before deployment, during monitoring, or mostly after something breaks

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Materialized Views for Massive resource intensive report queries

<p>I am thinking of placing a resource intensive report query in a materialized view. Now after I set up the base data, how can I ensure new data is added daily? (I already have pg_cron)</p>

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pgclone 4.0.0 released

pgclone v4.0.0: Native SQL-Based Database Cloning and Data Masking Baku, Azerbaijan — April 22, 2026 I am pleased to announce the release of pgclone version 4.0.0, a PostgreSQL extension that clones databases, schemas, and objects directly via SQL. It features built-in data masking, parallel background workers, and full DDL support — with no dependency on pg_dump, pg_restore, or external shell scripts. pgclone is released as open source under the PostgreSQL Licence. Description pgclone provides

PostgreSQL News

Connect to Azure Managed Redis with Redis Insight 3.2.0 — Now with Entra ID Authentication

We're excited to highlight a key feature in the Redis Insight 3.2.0 release (February 2026): native support for connecting to Azure Managed Redis using Microsoft Entra ID authentication. This is a significant step forward for Azure-based teams who wan...

Redis Blog

mariadb replication

<p>I'm trying to understand the feasibility of this setup which I'm envisioning.</p> <p>Site-A ( Active ) and Site-B ( Passive ) - MariaDB 10.11 with GTID.</p> <p>2x Masters (A &amp; B) with master/slave replication ( both ways ) between them.<br /> Application writes/reads only from one the masters at a time via KeepAlived/HAProxy VIP. Yes, the application has an inbuilt HA support for this. However the application is active only on one of the sites. This setup is working fine.</p

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Bloom filters in PSQL

This YT video here talks about how bloomfilter on psql helped incident.io bringing down latencies from 5 sec to under 300ms. Not really understanding how does their implementation of bloomfilters even help them. Correct me if I am wrong but - I am not even sure this can be called bloom filters. The way query has been written - I am sure the query will be a full table scan. In which case performance and latency takes massive hit. Has anyone here experience using bloom filters in production? Care

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Native OpenTelemetry metrics for Redis client libraries

When Redis server metrics look healthy but an application isn’t performing adequately (for instance, service time outs or p99 latency climbing for no obvious reason) the explanation is often not inside Redis at all. These symptoms frequently trace bac...

Redis Blog

Polymorphic associations in PostgreSQL: anti-pattern or acceptable design? Images and sales pivot tables as real examples

<p>I've been reading conflicting opinions about polymorphic associations and I'm genuinely confused. I'm working with PostgreSQL (raw SQL, no ORM, stored procedures) and need to make an informed design decision.</p> <p><strong>My two concrete cases:</strong></p> <p>Case 1 — Images shared across many tables: Several tables (products, users, categories) need images.</p> <p>I have several tables that need to store images:</p> <pre><code>CREATE TABLE products (id bigint PRIMARY KEY, n

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