postgres@hillpig-desktop:~$ postmaster --help
postmaster is the PostgreSQL server.

Usage:
 postmaster [OPTION]...

Options:
 -A 1|0          enable/disable run-time assert checking
 -B NBUFFERS     number of shared buffers
 -c NAME=VALUE   set run-time parameter
 -d 1-5          debugging level
 -D DATADIR      database directory
 -e              use European date input format (DMY)
 -F              turn fsync off
 -h HOSTNAME     host name or IP address to listen on
 -i              enable TCP/IP connections
 -k DIRECTORY    Unix-domain socket location
 -N MAX-CONNECT  maximum number of allowed connections
 -o OPTIONS      pass "OPTIONS" to each server process (obsolete)
 -p PORT         port number to listen on
 -s              show statistics after each query
 -S WORK-MEM     set amount of memory for sorts (in kB)
 --NAME=VALUE    set run-time parameter
 --describe-config  describe configuration parameters, then exit
 --help          show this help, then exit
 --version       output version information, then exit

Developer options:
 -f s|i|n|m|h    forbid use of some plan types
 -n              do not reinitialize shared memory after abnormal exit
 -O              allow system table structure changes
 -P              disable system indexes
 -t pa|pl|ex     show timings after each query
 -T              send SIGSTOP to all backend servers if one dies
 -W NUM          wait NUM seconds to allow attach from a debugger

Options for single-user mode:
 --single        selects single-user mode (must be first argument)
 DBNAME          database name (defaults to user name)
 -d 0-5          override debugging level
 -E              echo statement before execution
 -j              do not use newline as interactive query delimiter
 -r FILENAME     send stdout and stderr to given file

Options for bootstrapping mode:
 --boot          selects bootstrapping mode (must be first argument)
 DBNAME          database name (mandatory argument in bootstrapping mode)
 -r FILENAME     send stdout and stderr to given file
 -x NUM          internal use

Please read the documentation for the complete list of run-time
configuration settings and how to set them on the command line or in
the configuration file.

这里重点说一下 -W 参数。
我们知道一旦postmaster fork一个postgres，实际上你只能debug postgresmain（）里头for（）循环里的代码了，如何调试从postgresmain()函数开始到for（）循环这段代码呢？这里就用到-W参数。
设置示例如下：
postmaster -D /usr/local/pgsql/data -W 60
然后你在BaseInit（）调用处设置一个断点，O(∩_∩)O，是不是断点出来了。
实际上你只能调试从 pg_usleep(PostAuthDelay * 1000000L);到 for（）循环之间的代码，好在pg_usleep(PostAuthDelay * 1000000L);之前的代码没有什么真正有价值的东东，故该方法可以解决这段调试的大问题。

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