Update docs

docs/en/sql-reference/functions/other-functions.md

@@ -777,6 +777,37 @@ Alias: `FORMAT_BYTES`.
 └────────────────┴────────────┘
 ```
 
+## fromReadableSize(x)
+
+Given a string containing the readable respresentation of a byte size, this function returns the corrseponding number of bytes.
+ - As the conversion might lead to decimal bytes the result will be rounded up to the next integer to represent the minimum number of bytes that can fit the passed size.
+ - Accepts up to the Exabyte/Exabibyte (EB/EiB)  
+
+**Arguments**
+
+- `val` : readable size. [String](../data-types/string)
+
+**Returned value**
+
+- Number of bytes represented by the readable size [UInt64](../data-types/int-uint.md).
+
+Example:
+
+```sql
+SELECT
+    arrayJoin(['1 B', '1 KiB', '3 MiB', '5.314 KB']) AS readable_sizes,
+    fromReadableSize(readable_sizes) AS sizes
+```
+
+```text
+┌─readable_sizes─┬───sizes─┐
+│ 1 B            │       1 │
+│ 1 KiB          │    1024 │
+│ 3 MiB          │ 3145728 │
+│ 5.314 KB       │    5314 │
+└────────────────┴─────────┘
+```
+
 ## formatReadableQuantity(x)
 
 Given a number, this function returns a rounded number with suffix (thousand, million, billion, etc.) as string.

src/Functions/fromReadableSize.cpp

@@ -225,7 +225,28 @@ namespace
 
 REGISTER_FUNCTION(FromReadableSize)
 {
-    factory.registerFunction<FunctionFromReadableSize>();
+    factory.registerFunction<FunctionFromReadableSize>(FunctionDocumentation
+        {
+            .description=R"(
+Given a string containing the readable respresentation of a byte size, this function returns the corrseponding number of bytes:
+[example:basic_binary]
+[example:basic_decimal]
+
+If the resulting number of bytes has a non-zero decimal part, the result is rounded up to indicate the number of bytes necessary to accommodate the provided size.
+[example:round]
+
+Accepts readable sizes up to the ExaByte (EB/EiB).
+
+It always returns an UInt64 value.
+)",
+            .examples{
+                {"basic_binary", "SELECT fromReadableSize('1 KiB')", "1024"},
+                {"basic_decimal", "SELECT fromReadableSize('1.523 KB')", "1523"},
+                {"round", "SELECT fromReadableSize('1.0001 KiB')", "1025"},
+            },
+            .categories{"OtherFunctions"}
+        }
+    );
 }
 
 }