anchor.diff:  ----
   +
   'Posted 2015.03.26. Nick Psaris'
  -+
  -** p. 194, Asof joins, The third sentence of the first paragraph
  -   should begin: In fact, **the** asof join +aj+ operator.
  -+   
  -'Posted 2015.05.13. Danila Deliya'
  -+
  -** p. 198, Asof joins, The first sentence should read: Looking forward
  -   in time is generally a bad practice when attempting **to**
  -   reproduce a realistic simulation of historical events.
  -+   
  -'Posted 2015.05.13. Danila Deliya'
  ---
  -* Chapter 15
  -+
  ---
  -** p. 209, The +sym+ File, The second listing should begin with the
  +* p. 194, Asof joins, The third sentence of the first paragraph
  +  should begin: In fact, *the* asof join +aj+ operator.
  ++
  +'Posted 2015.05.13. Danila Deliya'
  +* p. 198, Asof joins, The first sentence should read: Looking forward
  +  in time is generally a bad practice when attempting *to*
  +  reproduce a realistic simulation of historical events.
  ++
  +'Posted 2015.05.13. Danila Deliya'
  +
  +== Chapter 15
  +
  +* p. 209, The +sym+ File, The second listing should begin with the
      following command:
   +
   ----
  
positive.code: ----
  +
  'Posted 2015.03.26. Nick Psaris'
  --
  
negative.code: ----
  +
  'Posted 2015.05.13. Danila Deliya'
  * p. 211, Virtual Column, The section should begin: *Each table in
  our +qdb+ database starts with a +date+ column.* But where did this
  column come from?
  +
  'Posted 2015.05.13. Danila Deliya'
  * p. 218, Compressing by Default, The last sentence should read: To
  clear the compression configuration we can use the *`\x`* system
  command and +.z.zd+ will be cleared.
  +
  'Posted 2015.05.13. Danila Deliya'
  
  == Chapter 16
  
  * p. 227, Subscriptions, The first sentence should read: Asynchronous
     messages are often used to send messages as fast *as* possible ...
  +
  'Posted 2015.04.04. Lam Hin Yan'
  
  == Chapter 17
  
  == Appendix A
  
  * p. 274, Utilities, The implementation of +.util.pivot+ should read:
  +
  ----
  pivot:{[t]
  