diff --git a/lib/sql.ml b/lib/sql.ml
index 1175cde1..540af6ae 100644
--- a/lib/sql.ml
+++ b/lib/sql.ml
@@ -656,7 +656,7 @@ type col_name = {
   tname : table_name option;
 } [@@deriving show]
 type logical_op = And | Or | Xor [@@deriving show]
-type comparison_op = Comp_equal | Comp_num_cmp | Comp_num_eq | Not_distinct_op | Is_null | Is_not_null [@@deriving eq, show]
+type comparison_op = Comp_equal | Comp_num_cmp | Comp_text_cmp | Comp_num_eq | Not_distinct_op | Is_null | Is_not_null [@@deriving eq, show]
 type null_handling_fn_kind = Coalesce of Type.tyvar * Type.tyvar | Null_if | If_null [@@deriving show]
 type source_alias = { table_name : table_name; column_aliases : schema option } [@@deriving show]
 type select_row_locking_kind = For_update | For_share [@@deriving show]
@@ -1176,7 +1176,10 @@ let () =
   "uuid_short" |> monomorphic int [];
   "is_uuid" |> monomorphic bool [text];
   "makedate" |> monomorphic datetime [int; int];
-  (* 
+  "similarity" |> monomorphic float [text; text];
+  "word_similarity" |> monomorphic float [text; text];
+  "strict_word_similarity" |> monomorphic float [text; text];
+  (*
      Any is used instead of Var because MySQL JSON functions have unique semantics:
    
    1. ACCEPT ANY DATA TYPE: MySQL JSON functions accept values of any type
diff --git a/lib/sql_lexer.mll b/lib/sql_lexer.mll
index a570ec6a..654ffe37 100644
--- a/lib/sql_lexer.mll
+++ b/lib/sql_lexer.mll
@@ -282,8 +282,8 @@ let cmnt = "--" | "//" | "#"
 rule ruleStatement = parse
   | ['\n' ' ' '\r' '\t']+ as tok { `Space tok }
   | cmnt wsp* "[sqlgg]" wsp+ (ident+ as n) wsp* "=" wsp* ([^'\n']* as v) '\n' { `Props [(n, String.trim v)] }
-  | cmnt wsp* "@" (ident+ as name) wsp* "|" ([^'\n']* as v) '\n' 
-    { 
+  | cmnt wsp* "@" (ident+ as name) wsp* "|" ([^'\n']* as v) '\n'
+    {
       let props = rulePropList [] (Lexing.from_string v) in
       let all_props = ("name", name) :: props in
       `Props all_props
@@ -302,8 +302,8 @@ rule ruleStatement = parse
 (* Parse a list of key:value properties *)
 and
 rulePropList acc = parse
-  | wsp* (ident+ as prop) wsp* ':' wsp* ([^',' '\n']+ as value) wsp* 
-    { 
+  | wsp* (ident+ as prop) wsp* ':' wsp* ([^',' '\n']+ as value) wsp*
+    {
       let new_acc = (String.trim prop, String.trim value) :: acc in
       rulePropListNext new_acc lexbuf
     }
@@ -312,7 +312,7 @@ rulePropList acc = parse
   | _ { error lexbuf "rulePropList" }
 (* Parse continuation after comma *)
 and
-rulePropListNext acc = parse  
+rulePropListNext acc = parse
   | ',' { rulePropList acc lexbuf }
   | wsp* '\n' { List.rev acc }
   | wsp* eof { List.rev acc }
@@ -346,13 +346,15 @@ ruleMain = parse
   | "+" { PLUS }
   | "-" { MINUS }
 
-  | "/" | "%" { NUM_DIV_OP }
+  | "/" | "%" { NUM_DIV_OP } (* FIXME: in PostgreSQL, "%" is both int modulo and a trigram comparison operator *)
   | "<<" | ">>" { NUM_BIT_SHIFT }
   | "|" { NUM_BIT_OR }
   | "&" { NUM_BIT_AND }
   | ">" | ">=" | "<=" | "<" { NUM_CMP_OP }
   | "<>" | "!=" | "==" { NUM_EQ_OP }
   | "<=>" { NOT_DISTINCT_OP }
+  | "<%" | "%>" | "<<%" | "%>>" { TEXT_CMP_OP }
+  | "<->" | "<<->" | "<->>" | "<<<->" | "<->>>" { TEXT_DIST_OP }
 
   | "->"  { JSON_EXTRACT_OP }
   | "->>" { JSON_UNQUOTE_EXTRACT_OP }
diff --git a/lib/sql_parser.mly b/lib/sql_parser.mly
index 2f2b5839..e3ab6bc9 100644
--- a/lib/sql_parser.mly
+++ b/lib/sql_parser.mly
@@ -53,6 +53,7 @@
 %token GROUP_CONCAT SEPARATOR
 %token JSON_ARRAYAGG
 %token NUM_DIV_OP NUM_EQ_OP NUM_CMP_OP PLUS MINUS NOT_DISTINCT_OP NUM_BIT_SHIFT NUM_BIT_OR NUM_BIT_AND
+%token TEXT_CMP_OP TEXT_DIST_OP
 %token JSON_EXTRACT_OP JSON_UNQUOTE_EXTRACT_OP
 %token <Sql.int_size option> T_INTEGER
 %token T_TEXT T_TINYTEXT T_MEDIUMTEXT T_LONGTEXT T_CHAR T_VARCHAR T_VARCHAR2
@@ -73,7 +74,7 @@
 %nonassoc NOT
 %nonassoc BETWEEN CASE (* WHEN THEN ELSE *) (* never useful *)
 %nonassoc EQUAL NUM_EQ_OP NOT_DISTINCT_OP IS LIKE LIKE_OP IN
-%nonassoc NUM_CMP_OP
+%nonassoc NUM_CMP_OP TEXT_CMP_OP TEXT_DIST_OP
 %left NUM_BIT_OR
 %left NUM_BIT_AND
 %left NUM_BIT_SHIFT
@@ -495,6 +496,7 @@ expr:
       e1=expr numeric_bin_op e2=expr %prec PLUS { Fun { fn_name = "numeric_bin_op"; kind = (Ret (Source_type.depends Any)); parameters = [e1;e2]; is_over_clause = false } } (* TODO default Int *)
     | MOD LPAREN e1=expr COMMA e2=expr RPAREN { Fun { fn_name = "mod"; kind = (Ret (Source_type.depends Any)); parameters = [e1;e2]; is_over_clause = false } } (* mysql special *)
     | e1=expr NUM_DIV_OP e2=expr %prec PLUS { Fun { fn_name = "num_div"; kind = (Ret (Source_type.depends Float)); parameters = [e1;e2]; is_over_clause = false } }
+    | e1=expr TEXT_DIST_OP e2=expr { Fun { fn_name = "text_dist"; kind = (Ret (Source_type.depends Float)); parameters = [e1;e2]; is_over_clause = false } }
     | e1=expr DIV e2=expr %prec PLUS { Fun { fn_name = "div"; kind = (Ret (Source_type.depends Int)); parameters = [e1;e2]; is_over_clause = false } }
     | e1=expr bool_op=boolean_bin_op e2=expr %prec AND { Fun { fn_name = "boolean_bin_op"; kind = (Logical bool_op); parameters = [e1;e2]; is_over_clause = false } }
     | e1=expr comp_op=comparison_op anyall? e2=expr %prec EQUAL { Fun { fn_name = "comparison"; kind = Comparison comp_op; parameters = [e1; e2]; is_over_clause = false } }
@@ -641,6 +643,7 @@ numeric_bin_op: PLUS | MINUS | ASTERISK | MOD | NUM_BIT_OR | NUM_BIT_AND | NUM_B
 comparison_op: 
     | EQUAL { Comp_equal }
     | NUM_CMP_OP { Comp_num_cmp }
+    | TEXT_CMP_OP { Comp_text_cmp }
     | NOT_DISTINCT_OP { Not_distinct_op }
     | NUM_EQ_OP { 
       (* it would be nice to go into num_eq_op,