Postgresql：用戶“ postgres”的密碼身份驗證失敗 - Postgresql: password authentication failed for user “postgres”

問題：

I have installed PostgreSQL 8.4, Postgres client and Pgadmin 3. Authentication failed for user "postgres" for both console client and Pgadmin.我已經安裝了PostgreSQL 8.4，Postgres客戶端和Pgadmin3。對於控制檯客戶端和Pgadmin的用戶“ postgres”，身份驗證失敗。 I have typed user as "postgres" and password "postgres", because it worked before.我已經輸入了用戶“ postgres”和密碼“ postgres”，因爲它以前可以工作。 But now authentication is failed.但是現在身份驗證失敗。 I did it before a couple of times without this problem.我之前幾次都沒​​有出現此問題。 What should I do?我該怎麼辦？ And what happens?那會發生什麼呢？

psql -U postgres -h localhost -W
Password for user postgres: 
psql: FATAL:  password authentication failed for user "postgres"
FATAL:  password authentication failed for user "postgres"

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解決方案：

參考一： https://stackoom.com/question/WI4Q
參考二： Postgresql: password authentication failed for user “postgres”