Questions tagged [queue]
The queue tag has no usage guidance.
39
questions
2
votes
2
answers
123
views
Message queue per user
I am using the same user to connect 4 servers to a database.
Although the database is not overloaded, I think that if a heavy query delay occurs on one server, the other servers are affected, ...
3
votes
3
answers
406
views
Impact of index on a "status" field with one (guaranteed) change
Introduction
I have a PostgreSQL table setup as a queue/event-source.
I would very much like to keep the "order" of the events (even after the queue item has been processed) as a source for ...
- 33
0
votes
2
answers
760
views
Transactions are not completing when locking and updating one row at a time
I have a database function I have written to atomize a simple table update. My system is status driven, so I want the next row with the desired status, and update it to a new status, and return the ID....
- 1
0
votes
0
answers
50
views
Implement Competing Consumers using MongoDB?
I am just learning MongoDB and considering using it to implement competing consumers over messaging queues (i.e. pubsub). What are my options to efficiently do so? Is MongoDB's concurrency model ...
- 21
1
vote
1
answer
29
views
The approach to take when creating/editing many interrelated records in a transactional way?
So I have a fairly complex system I would think, that is starting to come about. It is too involved to write out all the tables, but here is a brief description.
Basically I am creating a badging ...
- 189
1
vote
0
answers
115
views
Service Broker's SEND statement causes security context switch
We have triggers in multiple tables that will send messages to a Service Broker service upon INSERT, UPDATE and DELETE operations. These operations may be nested as parts of bigger, transactional ...
- 111
1
vote
1
answer
255
views
Optimize UPDATE query for single "next" row
We had information from new relic that one our query has a bad performance (almost 16 seconds for execution). We use PostgreSQL 11.8 on Debian Linux.
Table:
postgres=# SELECT table_name, column_name, ...
1
vote
2
answers
535
views
Correct way to continuously receive from a queue
I have to receive messages from a queue continuously.
My current code looks like this:
DECLARE @status INT=1
WHILE @status IS NOT NULL
BEGIN
WAITFOR (RECEIVE @status=status,
...
- 133
2
votes
0
answers
211
views
Exactly-once FIFO queue in Synapse
Creating a queue table in SQL Server is a much-studied problem. However, I would like to implement one in Azure Synapse where many of the building blocks do not exists. Specifically
no table hints (...
- 24.7k
0
votes
1
answer
59
views
Queueing MySQL record inserts to avoid over-subscription of a related resource ... table locking?
Given a simplified hypothetical of seats in a lifeboat, if I have the following setup with a lifeboats table and a seats table where each record is one occupied seat in the given lifeboat:
CREATE ...
- 3
2
votes
1
answer
358
views
Duplicate key errors in Postgres queue-like table when rows should be locked by SELECT FOR UPDATE SKIP LOCKED
I have a table called queue with items that need to be processed:
CREATE TABLE public.queue (
id serial NOT NULL
CONSTRAINT queue_pkey
PRIMARY KEY
);
Another table process ...
- 123
0
votes
1
answer
278
views
Are recent versions of Oracle able to implement a queue with SKIP LOCKED?
My question: what is the very latest status on whether or not recent versions of Oracle actually make it possible to implement a queue in a straightforward way with SKIP LOCKED and limiting to a ...
- 169
1
vote
3
answers
292
views
Queue Implementation with Custom Consistent Absolute Ordering
I need to create a schema for a queue. Elements in this queue will be processed in an order based on a column. However, this is not always the e.g. date_added column.
Users should be able to freely re-...
- 123
0
votes
2
answers
201
views
A way to merge multiple queues
Consider the following table:
CREATE TABLE `multiqueue` (
`ID` BIGINT(20) NOT NULL AUTO_INCREMENT,
`CustomerID` BIGINT(20) NOT NULL,
`Volume` INT(11) NOT NULL,
`Content` MEDIUMTEXT NOT ...
- 115
7
votes
2
answers
444
views
Using a Table as a Queue without sp_getapplock/sp_releaseapplock
I have a list of commands I need to execute, all of which are contained within a table I've named myQueue. This table is a little unique in that some commands should be grouped together such that ...
- 9,342
0
votes
0
answers
216
views
How to create and process queue of data (FIFO) from MS SQL Trigger [duplicate]
I would like to create a table and fill it with data and have it act as a queue that works in a first-in-first-out fashion. New items can be added at any time while processing or not.
My inserts ...
- 321
4
votes
3
answers
778
views
Why is our query suddenly returning rows it should not (using READPAST and UPDLOCK options)?
We have a job table that looks like this
CREATE TABLE [dbo].[Clearing](
[Skey] [decimal](19, 0) IDENTITY(1,1) NOT NULL,
[BsAcctId] [int] NULL,
[Status] [varchar](20) NULL,
CONSTRAINT ...
- 151
4
votes
1
answer
1k
views
How can I limit SQL Server Agent's simultaneous jobs number?
I'm looking for a setting (other than schedules shifting) which could limit the number of jobs running simultaneously.
I have 844 jobs in my SQL Agent (SQL Server 2017 Enterprise). Most of them needs ...
- 43
0
votes
0
answers
86
views
Automating Alerting on Blocking with Queues and Event Notifications [duplicate]
I need to automate email notifications on blocking on some SQL 2016 servers. I have had a look at running a job through the SQL agent but seems hack n slash. I found an alternative method online that ...
- 129
0
votes
2
answers
55
views
Best Database specifications for my IOT solution
i'm working on a IOT environment that basically is a sensor that can measure more then 300 times a second. We receive this measurements remotely using MQTT protocol. I want to set up a painel where i ...
- 103
2
votes
0
answers
60
views
How should I configure a table to optimize for frequent inserts and deletes? [duplicate]
I know about making the clustered index a steadily increment field, like a datetime field. So that will give me fast inserts.
However, the deletes will be based on a consumer of the "queue". So the ...
- 133
1
vote
1
answer
135
views
Is this table-backed-queue implementation safe?
We've a system where kinds of orders should be processed in batches, by advancing them from Status 0 to Status 1. There's a max number of a particular kind of order we can process in any one go, and ...
- 334
0
votes
1
answer
31
views
Row inserted to DB in main app is not available in the different process. Can MySQL defer some queries?
I have such problem. My main app process some request and insert the new row into DB, then send an Event to the queue. I have the different process that listens on that queue and when he get details ...
0
votes
1
answer
2k
views
How to persist messages in Postgresql's LISTEN/NOTIFY? [closed]
If I send notifications before starting to listen i.e.
notify test, 'test message';
listen test;
I loose that notifications. How can I persist them for later fetching?
Actually, I need this ...
- 103
2
votes
1
answer
484
views
How do I determine what is activating my SQL service broker proc?
I have several queues. One of which has suddenly started acting oddly. It activates repeatedly while nothing is in it's queue. I even manually removed old conversations and this thing is still ...
- 251
23
votes
3
answers
29k
views
Postgres Listen/Notify As Message Queue
Is there any way to use Postgres Listen/Notify feature to deliver a message to a channel and have only one listener consume this message?
The purpose for this is that I have multiple 'worker' apps ...
- 331
1
vote
1
answer
1k
views
Database table as a queue, order by another table's column
I have two tables. One table serves as the queue from which multiple users simultaneously dequeue items one at a time, by flagging the item's row. The other table is joined and used for ordering. It ...
- 121
31
votes
2
answers
58k
views
Automatic aging-out (deletion) of old records in Postgres
Does Postgres have any features to support aging-out old records?
I want to use Postgres for logging, as a sort of queue, where records (log events) older than two weeks are automatically deleted.
- 10.6k
7
votes
1
answer
3k
views
No service broker active on database
I am trying to set up query notification however when I try to create a queue and service I get the error 'There is no Service Broker active in the database. Change to a database context that contains ...
- 257
1
vote
0
answers
691
views
oracle AQ for scheduled jobs
We have a process that currently uses the Oracle DBMS_SCHEDULER to execute. The process runs every time the backend receives data from an external device. The Oracle scheduler is set up such that a ...
- 11
15
votes
3
answers
22k
views
Best way to implement concurrent table based queue
I have a table in MySQL that represents a queue of links to be processed. The links are processed by an external app, one by one, and deleted in the end. This is a high volume queue and I have ...
- 275
3
votes
1
answer
997
views
Work queue with complex select and long processing: Ensuring concurrency
I have a queue table from which worker processes claim records, one at a time. It is crucial that no two workers claim same item to process.
Normally this kind of thing is done with select top (1) ......
- 1,342
139
votes
1
answer
165k
views
Postgres UPDATE ... LIMIT 1
I have a Postgres database which contains details on clusters of servers, such as server status ('active', 'standby' etc). Active servers at any time may need to fail over to a standby, and I don't ...
- 1,555
2
votes
1
answer
1k
views
Retrieve next queue item
I have a simple table in SQL Server 2012 which implements a processing queue. As data has been inserted the query to retrieve the next item has gone from <100ms to a constant 5-6secs. I would be ...
- 285
0
votes
0
answers
147
views
Efficient way to fetch/update X records in a loop
What I need is a simple process that handles requests.
I have setup a simple table as follows:
CREATE TABLE Requests (
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
request_param VARCHAR(250) ...
- 761
7
votes
1
answer
2k
views
Recommendations on how to organize Queues in Service Broker
I have a service broker application that currently has 5 or 6 queues on two servers.
The general workflow is:
Server A
User populates some tables
User fires stored proc which puts a message into ...
- 17.9k
2
votes
1
answer
439
views
Schema for multiple identical queue tables
I am migrating a message processing application that was built on MSMQ to SQL Server 2012 (preferably Standard Edition). Messages are received and distributed via TCP/IP endpoints and the typical ...
- 535
2
votes
0
answers
90
views
Optimizations for new SQL Server 2000 database that will act as email queue AND API database
Due to limitations put on me I've got to put my outgoing Email Queue in the same database as my customer information.
What are some optimizations I can make, specifically to the Email portion that ...
- 121
19
votes
2
answers
22k
views
FIFO queue table for multiple workers in SQL Server
I was attempting to answer the following stackoverflow question:
What SQL Server 2005/2008 locking approach should I use to process individual table rows in multiple server application instances?
...
- 4,305