Documenting log formats

1 files changed, 6 insertions, 47 deletions

diff --git a/doc/querylanguage.md b/doc/querylanguage.md
index c6b9beb..96d0fd1 100644
--- a/doc/querylanguage.md
+++ b/doc/querylanguage.md
@@ -7,9 +7,7 @@ The query language allows you to run mapreduce queries on log files. This page i
 
 For this to work, DTail needs to understand your log format. DTail already understands its own log format. You can have a look at all examples of the [examples](./examples.md) page using `-query` (these would be all examples of the `dmap` command, and some examples using the `dtail` command).
 
-DTail also ships with a generic log format, which only allows you to run very basic queries. Check out the [log formats](./logformats.md) documentation for this.
-
-To implement your own log format, please also check out the [log formats](./logformats.md) documentation.
+DTail also ships with a generic log format, which only allows you to run very basic queries. Check out the [log format](./logformats.md) documentation for this. To implement your own log format, please also check out the log format documentation.
 
 ## The complete language
 
@@ -23,6 +21,7 @@ QUERY :=
     [interval SECONDS]
     [limit NUM]
     [outfile "FILENAME.csv"]
+    [logformat LOGFORMAT]
 SELECT := FIELD|AGGREGATION(FIELD)
 TABLE := The mapreduce table name, e.g. WRITE in MAPREDUCE:WRITE
 AGGREGATION := count|sum|min|max|avg|last|len
@@ -31,56 +30,16 @@ ARG := This is either
     a string: "foo bar"
     a float number: 3.14
     a bareword e.g.: responsecode
-    or a $variable (see below).
+    a field or a $variable
 OPERATOR := This is one of ...
     Floating point operators:
         == != < <= > >=
     String operators:
-        eq ne contains lacks (lacks is the opposite of contains, e.g. 
-                              "not contains")
+        eq ne contains lacks (lacks is the opposite of contains, e.g. "not contains")
 GROUPFIELD := bareword|$variable       
 ORDERFIELD := This must be a AGGREGATION(FIELD) or FIELD which was specified in
               select clause already.
+LOGFORMAT := The name of the log format implementation. It's 'default' by default.
 ```
 
-## Predefined variables
-
-This is the list of pre-defined variables. Please note that these vary depending on the log format used. 
-
-### Common variables:
-
-The common variables may exist in all log formats.
-
-* `$empty` - The empty string `""`
-* `$hostname` - The server FQDN
-* `$line` - The current log line
-* `$server` - Alias for `$hostname`
-* `$timeoffset` -  Offset of $timezone
-* `$timezone` -  The current time zone
-* `* (special placeholder)
-
-### DTail default log format:
-
-These variables may only exist when your logs are in the DTail default log format:
-
-*Date and time:*
-
-* `$hour` - The current hour in format HH
-* `$minute` - The current minute in format MM
-* `$second` - The current second in format SS.
-* `$time` - The current time in format YYYYMMDD-HHMMSS
-
-*Log level/severity:*
-
-* `$loglevel` - Alias for `$severity`
-* `$severity` - The log severity
-
-*System and Go runtime:*
-
-* `$caller` - DTail server caller of the logger
-* `$cgocalls` - Num of DTail server CGo calls
-* `$cpus` - Num of DTail server CPUs used
-* `$goroutines` - Num of DTail server Goroutines used
-* `$loadavg` - 1 min. average load average
-* `$pid` - DTail server process ID
-* `$uptime` - DTail server uptime
+Note, that the available fields and variables vary from the log format used. There is also a subtle difference between a field and a variable. Check out the [log format](./logformats.md) documentation for more information.