All Questions

SQL Server 2019 CTP3.1 introduced an optimization to address last-page insert contention. This takes the form of an index option called OPTIMIZE_FOR_SEQUENTIAL_KEY. One imagines this could be an ...

Partly as a result of having problems with conflicting versions or bitness with the full installation of Oracle client, my development team (of which I'm a member) has been moving towards using Oracle ...

I've just set up a publication, and I'm attempting to get the snapshot to apply faster. So far the Distribution Agent is respecting the MaxBCPThreads settings, but the Snapshot Agent is not. I'm ...

Why would an availability group's number of worker threads in an HADR pool increase well beyond minimum usage of "typically, there are 3–10 shared threads" per replica? In one case we've observed ...

In Amazon RDS SQL Server (any version/edition), create a temp table and update statistics on it. This works fine: IF OBJECT_ID('tempdb..#t') IS NOT NULL DROP TABLE #t; GO CREATE TABLE #t (id INT ...

The From Clause Documentation starting with SQL Server 2008 briefly mention 3 join hints and their basic mechanisms: Reduce Replicate Redistribute However there does not seem to be much information ...

I always thought that updating a stored procedure was something I could do while users were actively using the system. But I am currently testing out an update to a stored procedure and while a long ...

I am running an RDS instance of PostgreSQL 9.6.3: select version(); returns PostgreSQL 9.6.3 on x86_64-pc-linux-gnu [...]. I have found that after issuing a stop from the RDS console followed by a ...

If I do CAST(1 AS SIGNED INTEGER) I always end up getting a BIGINT returned, for example: $ mysql -u root -p --column-type-info Enter password: --- Copyright and help message snipped for brevity --- ...

I'm trying to force a plan using query store but it keeps failing with reason 8695 according to data in SYS.QUERY_STORE_PLAN the last_force_failure_reason_desc is 'General_Failure'. Does anyone know ...

Context I have stumbled on an issue in SQL Azure where the Sort-operator is spilling over into TempDB due to poor row estimates. We are querying a master table that is joined with a number of detail ...

Let's say I have a table A, that has two columns: one is an ID for ThingA, and one is an ID for ThingB. The primary key is (ThingA, ThingB). Next, I have a second table, but this time it's restricted ...

I have a follow-up question to a question I have previously asked on SO. Instead of the query from my initial question, I want to convert the following into relational algebra: List the names and ...

So we have a configuration of 2 shard (each is a replica set) and one sharded collection. There are around 10 million records in each shard. We are using mongo 2.6.4 version. We have sharded with ...

My ordering application uses Oracle 11g Database. This DB has a primary table ORDERS and multiple child tables like ORDER_DETAILS, PLAN etc. ORDERS table is LIST partitioned on STATUS column and all ...

I am working on existing MySQL database. My task is to create a new data model for a billing system on that existing application. I have created a conceptual data model (click to enlarge): ...

I've been writing a backup script for sharded replica-sets and it's almost done, except that I can't seem to get it to successfully start the balancer back up after everything's all said and done. ...

Sometime last week my CTRL+TAB behavior changed. I used to hit CTRL+TAB, release, then I would be in my previous document tab. Now I hit CTRL+TAB, release, and the nav window is still open requiring ...

I've got a FTS Catalog on a table containing ~106 row. It used to work like a charm, but lately, for an unknown reason it started to get very bad (query >30 sec) performances randomly. Reading ...

In a 3 node Availability group, a secondary replica will often become subject to redo lag due to the causes covered in Microsoft's documentation: Troubleshoot: Changes on the Primary Replica are not ...

We have a physical SQL Server 2016 Enterprise SP2 with two instances and each instance contains one AG. Sometimes it happens that one AG goes to resolving (without failover), the cluster resource is ...

I'm mostly posting this for community awareness, but feel free to give feedback if you think there is a solution other than coding around the problem as we are doing. Crossposting this from my bug ...

I'm asked to develop a data-storage for time-series data, yet despite significant research I'm unsure about the data model and storage technology to chose. About the data The source data which is ...

As I mentioned in this question I'm trying to understand the working of clock hands. Simply put clock hands move when there is memory pressure so that cache entries can be removed or the cost can be ...

I'm doing the conceptual model for a Decision tree database. The goal is store any Decision tree. I have four entity types: DecisionTree, Node, Branch and Leaf. Each Decision tree is composed of ...

Trying to diagnose an problem, I've ran into that inconsistency. In SQL Server Profiler, the RPC Starting event uses the regional settings to write real numbers (example: in Portuguese(Brazil) 14.5 ...

We are using a change tracking solution to export increments for BI purposes for years now. But it was running directly on the production database. To lower the load on the system we wanted it to run ...

Has anyone ever put together a version compatibility matrix for pgAdmin versions and PostgreSQL versions? https://www.pgadmin.org/download/windows.php https://www.postgresql.org/download/windows/

I have a PostgreSQL table with a key (bigint) and a value (double). The table has tens of billions of rows. I have a single btree on the (key,value) for aid lookups by key. The table is never updated. ...

I was hoping someone here might have encountered this sort of issue and if so what did you do to fix it? Here's some details: DB server: SQL 2014 Enterprise (12.0.4100.1) OS: Windows 2008R2 ...

Following the the info in posts like these i would like to use the role system and policies, i.e. each user in my system would have a db role. I want to model the following properties but i can't come ...

TL;DR: Does a table referred to via schema.table get held in table cache? I have a large number of client databases that our application connects to based on an http request. These are used for every ...

I'm looking into providing DB level change tracking within my system. I need to be able to track changes at an entity level, rather than just individual tables. Right now, we have triggers on each of ...

I have a very simple query " select * from ap_statistic " running in my servers. the servers have the same hardware and software configuration (CPU 8 core, mem :32G, OS: redhat 5.5, mysql version: 5....

This question is different but similar to this request looking for SQL-86. SQL 1989 is almost 30 years old. Is this spec freely available anywhere. The standard does not have a Wikipage or the like? ...

Oracle 11g R2 Unfortunately our application has per row security "features". We have a query that looks about like this: Bad, slow: SELECT someRow, someOtherRow FROM bigTableA a WHERE EXISTS ( ...

I am working on an ERD which represents the relationships between entities in a Web development company behavioral model. There I have entities like: Customer Service ----------- (like: web ...

Given two tables Parent KeyID GroupID Name Active Child KeyID ParentID Name Child.ParentID is FKed to Parent.KeyID We insert both Parent and Child in a single transaction. If a ...

The current situation We're currently looking into a new product that will send device data back to us to interpret. These are the numbers we're looking at: Devices will most likely send data every ...

I have a SQL 2012 server that is throwing the following error every 5 minutes or so: Error: 17886, Severity: 20, State: 1. The server will drop the connection, because the client driver has ...

I am creating SQL Server Unit Tests. We are testing various stored procedures. In Unit testing principles, it is good practice to setup a small database table, populate values, and tear down (...

Lately, I've been trying to clean up a group of projects that my company received from an outside contractor. Among them is an SSAS cube, with an associated data warehouse. The contractors generated ...

I need to rebuild some big indexes and I'm doing some tests with the various options (sort_in_tempdb, maxdop, online) of the ALTER INDEX statement on an test index with 4 levels and 800000 pages on ...

As an analyst I love having the ability to turn up the work_mem on occasion when a big sort or index build is in the offing. As a DBA, the idea of random users being able to request an arbitrarily ...

I have been fooling around with Postgres 10 logical replication, trying to learn about it and potentially apply it to a couple of projects. I have observed something that I am wondering about, but I ...

I am trying to understand the impact of deletions to bloat of tables and indexes after large number of inserts and deletes. The inserts and deletes are following a rather strict pattern: first the ...

Running SQL Server 2012 standard, using both replication data and log shipping. Transaction log backups are created every few minutes. This question is NOT about the amount of space reported by the ...

I have two tables and a trigger and am inserting values in ProjectsTable like this: CREATE TABLE ProjectsTable ( ProjectID NUMBER(6) NOT NULL, ProjectName VARCHAR2(200) NOT NULL, Cost ...

I have a 3 node cluster and the 2 secondaries initially went into SUSPECT mode due to a deadlock. I tried to resume both and only one caught up while the other is continuously deadlocking. I have to ...

I have an Agent job which is usually triggered by a WMI event. The job has a token within it, which automatically takes a value from the WMI event and substitutes it into the step's Powershell code, ...