Unanswered Questions
17,555 questions with no upvoted or accepted answers
23
votes
0answers
1k views
Splitting Snapshot files with MaxBCPThreads for Transactional Replication
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 ...
14
votes
0answers
371 views
Constant Scan applying
This question is a continuation of optimizer behavior exploration in regards to VALUES construct started here and here. I want to ask about VALUES and APPLY this time.
Using CROSS APPLY to alias an ...
13
votes
1answer
151 views
How to limit memory consumption of mysql server to prevent OOM kills?
My MySQL instance is getting killed by the Linux oom_killer due to huge consumption of memory by mysql when inserting into longblob columns. This occurs when restoring a mysqldump which contains a ...
12
votes
1answer
1k views
HADR high worker thread usage
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 ...
11
votes
0answers
2k views
Best practices for keeping protobuf spec in sync with relational database (e.g. PostgreSQL)
1. We have a schema definition in Google's Protocol Buffers format that we use to generate code for different gRPC implementations (Python, PHP)
2. We have a database (PostreSQL) that is initialized ...
11
votes
0answers
4k views
PostgreSQL trigram GIST vs. GIN indexes
I have a PostgreSQL 9.1 database that contains 10M+ rows and some text fields that need similarity and %word%-like searches, so I decided to use trigram indexes.
Initially, I started to use GIN ...
11
votes
1answer
14k views
Conceptual data model for a billing system
I am working on an 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):
##...
11
votes
1answer
600 views
MySQL deadlock: upsert query acquiring gap lock twice?
I am trying to debug a deadlock scenario which has been puzzling me for quite some time now. I am wondering if someone can shed any light into how this can happen.
Here is the deadlock output:
------...
10
votes
0answers
273 views
dm_os_memory_cache_clock_hands understanding
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 ...
Frederik Vanderhaegen
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9
votes
1answer
465 views
Efficiently store large list structure in RocksDB so that the data can be retrieved in pages
Description:
RocksDB is a key-value storage so we can simply serialise the list of objects & store the value corresponding to a key. This would be ok if the data in the list is small enough.
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9
votes
0answers
7k views
DBeaver launch script from file
I'm trying to find a good alternative to SQL Developer for performing queries and scripts on Oracle instances.
I find DBeaver to be an interesting tool, it has a lot of great features, BUT it seems ...
9
votes
1answer
1k views
Convert query in words to relational algebra
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 ...
9
votes
1answer
714 views
SSMS 2014 (and 2012) CTRL+TAB requires pressing enter
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 ...
8
votes
1answer
779 views
Database Stuck 'In Recovery' with command XTP_DB_RECOVERY
We recently converted a table to memory optimized data. Our backups have all ballooned (3x300GB files to 3x600GB files for Full, 3x50GB to 3x250GB for Diffs), and startup has been getting ...
8
votes
0answers
3k views
Working on a decision tree database design
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 ...
