Is the downvote-answer feature necessary on Quora?

Yes.  Without downvoting, I think you open Quora up to non-constructive answers which weaken the strength of the site. See What are good and bad reasons to downvote answers on Quora? That question has a number of answers that get at this point. That question and its answers also support the secondary point that Justin Bishop is making — which I agree with — that unfair/unreasonable downvoting is demoralizing.

In football, what is a slot back?

A slot back is basically a slot receiver who lines up in the backfield.

This page is pretty instructional.
http://www1.phillyburbs.com/foot…

It says:
"The flanker can also become a slot receiver or slot back. If he’s positioned between the split end and a tackle, his name changes. The coach can take out a tight end, making a slot back the third receiver, attempting to create mismatches with the defense. But even in a standard set that includes a tight end, the receiver can line up between the split end and the tackle and be called a slot back. This gives him a few steps running start before the defender can smack him one."

Wikipedia says a slot back is:
"A receiver lining up in the offensive back field. Canadian and Arena football allow them to take a running start at the line. They are usually larger players as they need to make catches over the middle. In American football slot backs are typically used in flexbone or other triple option offenses while Canadian football uses them in almost all formations."
http://en.wikipedia.org/wiki/Wid…

What are the best "value for your money" restaurants in Philadelphia?

My wife and I, as well as our friends, love to eat at the Sang Kee Noodle House Asian Restaurant.  There are several locations in Philly but we most often visit the one in Wynnewood on the Main Line.

The Asian food is consistently delicious, reasonably priced, and served with quickly, efficiently, and pleasantly by an excellent staff.  You will be treated with kindness when you enter, fed well while you're there, and leave completely satisfied … eager to return next time.

BTW, try to avoid times when it will be very busy like Friday and Saturday evenings.

Can regularly using an alcohol-based mouthwash damage sense of taste ?

Very likely no.

This is an interesting question because there is a fair amount of interest/debate about alcohol-based mouthwashes on the Web. Various articles online cite a range of potential drawbacks w.r.t. alcohol in mouthwashes — e.g., cancer risk; general counter-effectiveness; dehydration.  But from what I can see, there is no speculation that alcohol can damage one's sense of taste.

To be clear, I'm not weighing in on whether any of these other risks are real — just noting that of the significant # of ideas / wild theories floating out there, sense-of-taste risk is not among them.

What are the most common sources of memcached cache inconsistency?

1. Application-level bugs (including bugs in previous versions of the code that didn't delete values that they changed, even if those bugs have since been fixed).

2. The following race condition.
  a. thread 1 looks at the memcache key and gets a miss
  b. thread 1 falls back to the database
  c. thread 2 changes the database value
  d. thread 2 deletes the memcache key
  e. thread 1 sets the old database value into memcache

This can be solved by using the CAS operation which tracks a version number for changes, available in recent versions of memcached.

3. Multiple versions of the code executing simultaneously, such as during a code push. If new code is being rolled out that includes the code to delete and set new cache keys, the new code might set some values which should be deleted, but the old code that's still running for the duration of the push might not delete those values if they change.

One solution to this problem is to only push the code that deletes the cache keys first, and then once that's completely finished, push the code that sets the values.

A similar problem can occur when developers are changing their code in their sandboxes and that code writes values into a memcached pool shared with other developers or production code.

4. Network problems might cause memcache clients to be unable to contact the appropriate memcached server to issue a delete. A typical behavior by memcache clients is to mark a server as "down" for some period of time after a brief network outage and ignore all operations affecting it. However, during that time, other clients might see it as up, and issue sets to data which subsequently should have been deleted by a client that sees it as down.

One solution to this is to write a log of keys that should be deleted locally and replay this log after the server comes back up. Another solution is to create a global consistent view of which memcached servers are "up" and mark a server as globally down if a client can't connect to it, and then clear all of its contents when it comes back up.

What are the chances Google will split its stock in the near future?

If you have only enough money to buy a few shares of Google, you are not well capitalized enough to invest. It would be a more worthwhile use of your time to learn how to make more money and/or spend less.

That is just my opinion.

If you think you can time events like a stock-splitting but don't have enough money to actually buy more than a few shares, then please ignore all those discount brokerage ads and save more money.

Anon user's answer quoting from Google's S-1 filing is a good enough explanation as to why a stock split is unlikely.

It's more likely that Google's stock price collapses to a more affordable range due to some technological development that renders its main business model obsolete than it is that it will do a stock split.