A graph database suitable for analyzing a heap snapshot?

It looks like recommendation questions aren’t explicitly OT, so here goes:

I’m working on some tooling for analyzing a dump of the heap of a running program. The dump is just a list of nodes with associated metadata and references to other nodes (possibly-cyclical).

I don’t have any experience with graph databases, and I’m wondering if I would save myself a lot of time by building tooling around a graph DB. So I’m looking for recommendations and pointers to resources, and advice.

Some specific questions:

  • are there any graph databases that have functionality built in for computing a dominator tree? (googling this didn’t seem to get any results)
  • are there any DBs that have tooling for visualizing a huge graph?

Free embedded database with EF & async I/O support

I’m looking for a free embedded database that has async I/O support to be used in a desktop (C#/.NET, WPF) application. I’ll be using the Entity Framework Core ORM so a suitable provider also is required.

I did some research and so far it seems like these are my options:

  • Sqlite
  • Firebird
  • SQL Server Compact 4.0 (Dead?)

Are there any more options that are preferably free? There’s also MySQL but I think the embedded version is not free?

I’m currently considering Sqlite as it’s a popular and (I think) being actively developed so we will not be stuck with a deprecated piece of technology when moving forward with our application, but it doesn’t seem to have async I/O support, which would be really nice to have to avoid blocking the UI thread.

Forgive me if I’m posting in the wrong site, I figured I’d find more informed people here than in the Software Recommendations site. Thank you!

PS: Here’s a list of EF Core providers from Microsoft, but I don’t know if it’s exhaustive.

Fail to establish database connection

I did a backup for my client’s website for both the web files and sql. Now, I am trying to restore it to my cpanel. I have no problem restoring the web files but the sql automatically change the name to xx_databasename. And when I tried to see the website live, it says there is a problem to establish a database connection.

Does anyone know how to solve this issue?

conversion failed when converting datetime from character string while inserting and updating to database

I’m trying to insert time and date separately and calculate if it is late to the set time and then insert it to database…

here’s my try code for update

string Date = DateTime.Now.ToString("dd-MM-yyyy"); string Time = DateTime.Now.ToString("h:mm:ss tt"); SqlCommand comm2 = conn.CreateCommand(); comm2.CommandText = "Update Time_Logs SET Time_Out = ‘" + Time + "’ where Emp_Id = ‘" + EmpId.Text + "’ and Date = ‘" + Date + "’"; try { conn.Open(); comm2.ExecuteNonQuery(); MessageBox.Show("Time_Out…"); conn.Close(); TimeCompute(); } catch (Exception x) { MessageBox.Show(x.Message); conn.Close(); }

and here is the code for inserting

string Date = DateTime.Now.ToString("dd-MM-yyyy"); string Time = DateTime.Now.ToString("h:mm:ss tt");

        SqlCommand comm = conn.CreateCommand();         comm.CommandText = "INSERT INTO Time_Logs (Emp_Id, Date, Time_In) VALUES('" + EmpId.Text + "','" + Date + "','" + Time + "')";         try         {             conn.Open();             comm.ExecuteNonQuery();             MessageBox.Show("Time_In...");             conn.Close();             DateTime time = DateTime.Parse(Time);             DateTime inDate = DateTime.Parse("8:00:00 AM");             TimeSpan ts1 = inDate.TimeOfDay;             TimeSpan ts = time - inDate;             if (ts < ts1)             {                 SqlCommand comm2 = conn.CreateCommand();                 comm2.CommandText = "Update Time_Logs SET Late = '" + ts + "' where Emp_Id = '" + EmpId.Text + "' and Date = '" + Date + "'";                 conn.Open();                 comm2.ExecuteNonQuery();                 conn.Close();             }             else             {                 SqlCommand comm2 = conn.CreateCommand();                 comm2.CommandText = "Update Time_Logs SET Late = '" + ts + "' where Emp_Id = '" + EmpId.Text + "' and Date = '00:00:00'";                 conn.Open();                 comm2.ExecuteNonQuery();                 conn.Close();             }         }         catch (Exception x)         {             MessageBox.Show(x.Message);             conn.Close();         } 

Database system is in recovery mode: Segmentation fault

PostgreSQL version : 12.4

Server: RHEL 7.9

I got postgres server into recovery mode for a minute and then came back normal.

Looking into logs, found this error before it went to recovery mode:

db=,user= LOG:  server process (PID 4321) was terminated by signal 11: Segmentation fault db=,user= DETAIL:  Failed process was running: select distinct some_col.some_state_id,case when some_col.some_state_id=99 then 'CENTRAL' else state.state_name_english end as stateNm,case when some_col.some_state_id=99 then 'AAA' else state.state_name_english end from xema.table_name_definition_mast defn_mast left join othe.get_state_list_fn() state on some_col.some_state_id=state.state_code where defn_mast.third_srvc_launch ='Y' and some_col.some_state_id < 100 order by 3 

I doubt if this issue will come up again. Is this query specific or hardware problem? Got stuck.

Insert custom data to custom table on wordpress database

i need some help here

i wanna create some form for user to subscribe our article and store the data to database. i have tried to search it on google, but nothing worked when i tried that. i know that some plugin can do that but i dont know how to create the validation when user already subscribed and the form never show again.

how do i do to insert the data to my database? hope you guys understand what the problem and any help will appreciate

thank you

here is my code

the form

                    <form action="<?php echo site_url() . '/insert-data.php'; ?>" method="POST" name="form-subscribe">                         <div class="row">                             <div class="col-12 col-lg-12 col-md-12">                                 <p>Name*</p>                                 <input type="text" name="subs_name" placeholder="Full Name*" required="">                                                            </div>                         </div>                         <div class="row mt-3">                             <div class="col-12 col-lg-12 col-md-12">                                 <p>Email*</p>                                 <input type="text" name="subs_email" placeholder="Email Address*" required="">                                                           </div>                         </div>                         <div class="row mt-3">                             <div class="col-12 col-lg-12 col-md-12">                                 <p><button type="submit" class="btn btn-primary" name="submitForm">Submit</button></p>                             </div>                         </div>                     </form> 

the action file aka insert-data.php

<?php      //setting up the form     function insertuser() {        $  name   = $  _POST['subs_name'];       $  email  = $  _POST['subs_email'];          global $  wpdb;        $  table_name = $  wpdb->prefix . "subscriber";       $  wpdb->insert($  table_name, array('subs_name' => $  name, 'subs_email' => $  email) );       }  if( isset($  _POST['submitForm']) ) insertuser();  ?> 

Here is the table of wp_subscriber enter image description here

Database error: You have an error in your SQL syntax term_taxonomy

It’s been a while since this syntax error has been happening, I tried to look it up, have read articles and forum’s posts on this issue, but I still couldn’t fix it. It says I have an error on my database, but I’m afraid it might be my server. This mysql error is happening when I edit articles. I wished I could explain this better, but I have no idea of what’s going, this is what I get when I check the error log (a part or two might be odd because I translated to English):

WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ') AND (2u98_posts.post_author <> 77777 OR ( (2u98_term_taxonomy.taxonomy = "...' at line 3 for query SELECT SQL_CALC_FOUND_ROWS 2u98_posts.ID FROM 2u98_posts LEFT JOIN 2u98_term_relationships ON (2u98_posts.ID = 2u98_term_relationships.object_id) LEFT JOIN 2u98_term_taxonomy ON ( 2u98_term_relationships.term_taxonomy_id = 2u98_term_taxonomy.term_taxonomy_id ) WHERE 1=1 AND ( 2u98_term_relationships.term_taxonomy_id IN (152) ) AND ( (2u98_term_taxonomy.taxonomy = "author" AND 2u98_term_taxonomy.term_id = '345')) AND 2u98_posts.post_type = 'post' AND (2u98_posts.post_status = 'publish' OR 2u98_posts.post_status = 'queued' OR 2u98_posts.post_status = 'processing' OR 2u98_posts.post_status = 'hold') AND (2u98_posts.post_author <> 77777 OR ( (2u98_term_taxonomy.taxonomy = "author" AND 2u98_term_taxonomy.term_id = '345')) AND EXISTS (SELECT 1 FROM 2u98_postmeta WHERE 2u98_postmeta.post_id = 2u98_posts.id AND 2u98_postmeta.meta_key = "_wp_attachment_metadata"))) AND (2u98_posts.post_author <> 77777 OR ( (2u98_term_taxonomy.taxonomy = "author" AND 2u98_term_taxonomy.term_id = '345')) AND EXISTS (SELECT 1 FROM 2u98_postmeta WHERE 2u98_postmeta.post_id = 2u98_posts.id AND 2u98_postmeta.meta_key = "_wp_attachment_metadata"))) GROUP BY 2u98_posts.ID ORDER BY 2u98_posts.post_date DESC LIMIT 0, 5 made by require('wp-blog-header.php'), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts

Storing sparse and vilotile data in an analytical database

I want to perform an analytics of my company deliverables: financial metrics, production volumes, etc. For that, I’m creating a database on Postgres.

The main problem is that, I’m not sure which parameters (metrics) I would need finally – I would add parameters on demand. Therefore, creating an ER-model seems difficult for me now – I don’t now how many columns and which columns would be, and should I use different tables for different groups of information therefore.

I’ve come up with the following EAV model:

Parameters |ID| title       | | 1| Revenue     | | 2| Expenditures|   
ITEMS |ID| parameter_id| title          | | 1|     1       | online shopping| | 2|     2       | new computers  | 
DATA |ID| item_id| date       | value| | 1|    1   | 2020-01-01 | 1000 |` 

I made a research and it’s said, that this model would be difficult for analytics – different aggregation functions, data change on time interval, etc.


  1. Is this model acceptable in my case?
  2. What performace issues may I face and how to overcome?
  3. Should I move to an ER-model later (create a separate table for each parameter with a separate column for each item)? Or, it’s also appropriate to use VIEWS with pivoting data?

how to scaffold the database triggers

I’m trying to find a way to include table triggers when reverse-engineering the database. but I can’t seem to find a way to do it.

I’m using SQLserver and .netCore 3.1 with efcore.

and each time I scaffold the dbcontext , the triggers aren’t scaffolded.

Here’s my command

dotnet ef dbcontext scaffold "server={server};database={database};user={user};password={password}" Microsoft.EntityFrameworkCore.SqlServer --project  "{project}" --output-dir "Models" --force