在网上找到的，这个解决方案对我来说很好。

当我试图在升级到OS X 10.10 Yosemite后启动postgresql服务器时，我遇到了下一个问题:

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?

好的，让我们来看看服务器日志:

cat /usr/local/var/postgres/server.log

FATAL: database files are incompatible with server
DETAIL: The data directory was initialized by PostgreSQL version 9.2, which is not compatible with this version 9.3.5.

所以，在升级postgresql后，我们需要遵循以下几个步骤:

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

mv /usr/local/var/postgres /usr/local/var/postgres92

brew update

brew upgrade postgresql

initdb /usr/local/var/postgres -E utf8

pg_upgrade -b /usr/local/Cellar/postgresql/9.2.3/bin -B /usr/local/Cellar/postgresql/9.3.5_1/bin -d /usr/local/var/postgres92 -D /usr/local/var/postgres

cp /usr/local/Cellar/postgresql/9.3.5_1/homebrew.mxcl.postgresql.plist ~/Library/LaunchAgents/

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

rm -rf /usr/local/var/postgres92

就是这样。

类似于这些答案(1,2)，我的Postgres数据库文件在升级到postgresql 13.3后与我的Postgres版本不兼容。

不幸的是，升级Postgres数据目录失败了。

$ brew postgresql-upgrade-database
...
Setting next OID for new cluster
*failure*

Consult the last few lines of "pg_upgrade_utility.log" for
the probable cause of the failure.
Failure, exiting
Error: Upgrading postgresql data from 12 to 13 failed!
==> Removing empty postgresql initdb database...
==> Moving postgresql data back from /usr/local/var/postgres.old to /usr/local/var/postgres...
Error: Failure while executing; `/usr/local/opt/postgresql/bin/pg_upgrade -r -b /usr/local/Cellar/postgresql@12/12.7/bin -B /usr/local/opt/postgresql/bin -d /usr/local/var/postgres.old -D /usr/local/var/postgres -j 8` exited with 1.

我的解决办法是重新安装postgresql 12.7。

$ brew reinstall postgresql@12
$ brew services start postgresql@12

在网上找到的，这个解决方案对我来说很好。

当我试图在升级到OS X 10.10 Yosemite后启动postgresql服务器时，我遇到了下一个问题:

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?

好的，让我们来看看服务器日志:

cat /usr/local/var/postgres/server.log

FATAL: database files are incompatible with server
DETAIL: The data directory was initialized by PostgreSQL version 9.2, which is not compatible with this version 9.3.5.

所以，在升级postgresql后，我们需要遵循以下几个步骤:

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

mv /usr/local/var/postgres /usr/local/var/postgres92

brew update

brew upgrade postgresql

initdb /usr/local/var/postgres -E utf8

pg_upgrade -b /usr/local/Cellar/postgresql/9.2.3/bin -B /usr/local/Cellar/postgresql/9.3.5_1/bin -d /usr/local/var/postgres92 -D /usr/local/var/postgres

cp /usr/local/Cellar/postgresql/9.3.5_1/homebrew.mxcl.postgresql.plist ~/Library/LaunchAgents/

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

rm -rf /usr/local/var/postgres92

就是这样。

如果你正在寻找核心选项(删除所有数据并获得一个新的数据库)，你可以这样做:

rm -rf /usr/local/var/postgres && initdb /usr/local/var/postgres -E utf8

然后你需要rake db:setup和rake db:migrate from你的Rails app来重新安装。

试试这个: https://gist.github.com/joho/3735740

这对我来说非常有效。 最后，它还生成2个bash脚本来检查数据库并删除旧的集群。 真的太棒了。

参见:http://www.postgresql.org/docs/9.2/static/pgupgrade.html了解更多。

对我来说，这是一个命令:

brew install --build-from-source postgresql@12

然后创办了Postgres:

brew services start postgresql@12

也可以查看5432端口是否监听:

netstat -nl |grep 5432