tag:blogger.com,1999:blog-497787815177352569.post3400571129941615136..comments2024-01-03T08:55:04.827-05:00Comments on SQL Anywhere: How many times have you done this?Breck Carterhttp://www.blogger.com/profile/15975598564711761434noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-497787815177352569.post-40958299518390324712013-06-01T03:35:34.693-04:002013-06-01T03:35:34.693-04:00Hi,
I subscribe to your blog, and when I was read...Hi,<br /><br />I subscribe to your blog, and when I was reading this, it seemed vaguely familiar.<br /><br />And when I found the final note I had to look it up...<br /><br />So here I am one and a half year later, to explain my addition to the list - Failsafe parent-child traversals: <br /><br />I guess it's generic and would apply to all coding languages.<br /><br />We had a table with parent-child structure, and a stored procedure that traversed the parents until it hit the root node.<br /><br />And everything was working fine. It displayed every parent up to the root node. But along comes the customer...<br /><br />A few months later or db-server would eat up all CPU and eventually be so swamped that we where unable to shut down the database! We had to pull the cord to reboot the server.<br /><br />We tried to find a pattern to the CPU churning but it could be weeks between or the server could barely boot before it was swamped again.<br /><br />It turns out that a customer have put a loop in the parent-child structure, so that the traversing of parent-child structure would be stuck in a tight loop and eventually bring down our server.<br /><br />So we had to limit the length of our parent-child traversal.<br /><br />But I guess it applies to every loop where you rely on customer data.<br /><br />Best regards<br />Ove B-)Offehttps://www.blogger.com/profile/10353962692171794286noreply@blogger.comtag:blogger.com,1999:blog-497787815177352569.post-38257809364997402052010-12-07T03:33:26.678-05:002010-12-07T03:33:26.678-05:00Thanks a lot!
I thougth it was just me:-)
My vote...Thanks a lot!<br /><br />I thougth it was just me:-)<br />My votes goes to number 9 and 16.<br /><br />And my number 17th would be:<br />Forget to failsafe a parent-child traversal. It will eventually take down your server... at random times:-(<br /><br />Best regards<br />Ove B-)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-497787815177352569.post-59043172768323735262010-12-06T21:17:06.590-05:002010-12-06T21:17:06.590-05:00Many years ago using a different database (It was ...Many years ago using a different database (It was called Watcom SQL 2.0, running on Netware, but I'm dating myself) I had an application that had a table with a three-part composite primary key. <br /><br />We had users complaining that record would occasionally simply vanish from that table.<br /><br />We found the cause.. there was a DELETE statement in the application which ran very infrequently, but it only specified two of the three columns in the primary key... and that means more records that we wanted were getting deleted. <br /><br />GoogleSQL would likely give me an error message for this situation that was both useful and supported by a business model: "You appear to be missing an argument. Are you sure? {city} single mom finds the secret to {whiter teeth |excess belly fat| erectile disfunction|holiday shopping}. Click here now for the solution."<br /><br />I avoid composite keys like the plague for this and other reasons, but nonetheless, this one still stings many years later.ron hinernoreply@blogger.com