Paste this into a new question or an answer at dba.stackexchange.com:
<!-- -->
> SELECT E'TAB\x9TAB' AS "Single Byte", E'\xF0\x9F\x91\xBE' AS "UTF-8 bytes";
>
> <pre>
> Single Byte | UTF-8 bytes
> :------------- | :----------
> TAB TAB | 👾
> </pre>
<!-- -->
> SELECT E'\u0F02' AS "Code Point",
> E'\uD83D\uDC7E' AS "UTF-16 Surrogate Pair",
> E'\U0000D83D\U0000DC7E' AS "UTF-16 Surrogate Pair via UTF-32",
> E'\U0001F47E' AS "UTF-32";
>
> <pre>
> Code Point | UTF-16 Surrogate Pair | UTF-16 Surrogate Pair via UTF-32 | UTF-32
> :--------- | :-------------------- | :------------------------------- | :-----
> ༂ | 👾 | 👾 | 👾
> </pre>
<!-- -->
> SELECT E'\U0010FFFF' AS "Highest UTF-32 Code Point";
>
> <pre>
> | Highest UTF-32 Code Point |
> | :------------------------ |
> | |
> </pre>
<!-- -->
> SELECT E'\U00110000' AS "1 Value Higher Than Highest UTF-32 Code Point is Invalid";
>
> <pre>
> ERROR: invalid Unicode escape value at or near "E'\U00110000"
LINE 1: SELECT E'\U00110000' AS "1 Value Higher Than Highest UTF-32 ...
^
> </pre>
<!-- -->
> SELECT U&'\0F02' AS "Code Point",
> U&'\D83D\DC7E' AS "UTF-16 Surrogate Pair",
> U&'\+00D83D\+00DC7E' AS "UTF-16 Surrogate Pair via UTF-32",
> U&'\+01F47E' AS "UTF-32";
>
> <pre>
> Code Point | UTF-16 Surrogate Pair | UTF-16 Surrogate Pair via UTF-32 | UTF-32
> :--------- | :-------------------- | :------------------------------- | :-----
> ༂ | 👾 | 👾 | 👾
> </pre>
*db<>fiddle [here](https://dbfiddle.uk/?rdbms=postgres_11&fiddle=0ce292fcacf79dd624ba5bb0d34aceb0)*
back to fiddle