Honor quotes on unfielded PPL search terms without whitespace

core/src/main/java/org/opensearch/sql/ast/expression/SearchLiteral.java

@@ -32,7 +32,22 @@ public class SearchLiteral extends SearchExpression {
 
   @Override
   public String toQueryString(Function<String, ExprType> fieldTypeResolver) {
-    // Unfielded literal: no enclosing field, so no index type. Take the field-agnostic branch.
+    // Unfielded literal: no enclosing field, so no index type. The value is matched against
+    // index.query.default_field, which usually includes analyzed text, so the user's quoting is
+    // honored the same way as on a text field: a quoted value is a phrase even without whitespace.
+    // Otherwise a value the analyzer splits (`foo-bar`) becomes an OR of its tokens. On fields
+    // with a no-op analyzer the phrase and the bare term resolve to the same single term.
+    if (userQuoted
+        && literal instanceof Literal
+        && ((Literal) literal).getValue() instanceof String) {
+      String str = (String) ((Literal) literal).getValue();
+      // Same exception as on text: a whitespace-free wildcard value stays unquoted so `*` and `?`
+      // keep their operator meaning.
+      boolean wildcardTerm = hasUnescapedWildcard(str) && !str.contains(" ");
+      if (!wildcardTerm) {
+        return quoted(str);
+      }
+    }
     return toQueryString((ExprType) null);
   }
 

core/src/test/java/org/opensearch/sql/ast/expression/SearchLiteralTest.java

@@ -197,6 +197,50 @@ void argless_toQueryString_matches_null_type_branch() {
     assertEquals(lit.toQueryString((ExprType) null), lit.toQueryString());
   }
 
+  // -------------------------------------------------------------------------
+  // UNFIELDED (free text): no index type, so honor the user's quoting as on text.
+  // -------------------------------------------------------------------------
+
+  /**
+   * A quoted free-text value the analyzer splits must not become an OR of tokens. These values hold
+   * no whitespace, so the legacy space check emitted them unquoted.
+   */
+  @Test
+  void unfielded_quoted_value_the_analyzer_splits_emits_phrase() {
+    assertEquals("\"foo\\-bar\"", q("foo-bar").toQueryString());
+    assertEquals("\"foo=bar\"", q("foo=bar").toQueryString());
+    assertEquals("\"user@example.com\"", q("user@example.com").toQueryString());
+  }
+
+  @Test
+  void unfielded_quoted_with_whitespace_emits_phrase() {
+    assertEquals("\"foo bar\"", q("foo bar").toQueryString());
+    assertEquals("\"foo bar*\"", q("foo bar*").toQueryString());
+  }
+
+  @Test
+  void unfielded_quoted_wildcard_term_stays_unquoted() {
+    assertEquals("foo*", q("foo*").toQueryString());
+    assertEquals("log_?", q("log_?").toQueryString());
+  }
+
+  @Test
+  void unfielded_quoted_escaped_wildcard_emits_phrase() {
+    assertEquals("\"foo\\*\"", q("foo\\*").toQueryString());
+  }
+
+  @Test
+  void unfielded_unquoted_keeps_bare_term() {
+    assertEquals("foo", bare("foo").toQueryString());
+    assertEquals("foo\\-bar", bare("foo-bar").toQueryString());
+    assertEquals("foo*", bare("foo*").toQueryString());
+  }
+
+  @Test
+  void unfielded_non_string_literals_are_unchanged() {
+    assertEquals("42", new SearchLiteral(new Literal(42, DataType.INTEGER), false).toQueryString());
+  }
+
   // -------------------------------------------------------------------------
   // End-to-end via SearchComparison + resolver — the actual planner call path.
   // -------------------------------------------------------------------------

docs/user/ppl/cmd/search.md

@@ -40,6 +40,8 @@ The following queries show both syntax types:
 
 * **Unquoted**: `search error`, `search user-123`, `search log_*`
 * **Quoted**: `search "error message"`, `search "user@example.com"`
+
+A quoted value is matched as a phrase on analyzed text fields, even when it contains no spaces. For example, `search "user-123"` matches only documents in which the analyzed tokens `user` and `123` appear next to each other in that order, while the unquoted `search user-123` matches documents containing either token. A quoted value that contains a wildcard and no spaces, such as `search "log_*"`, is treated as a wildcard pattern instead of a phrase.
 
 ### Field values
 

ppl/src/test/java/org/opensearch/sql/ppl/parser/AstSearchExpressionTest.java

@@ -29,7 +29,7 @@ public void testSimpleSearchTerm() {
     assertTrue(plan instanceof Search);
     Search search = (Search) plan;
     // Double quotes are preserved for phrase search
-    assertEquals("error", search.getQueryString());
+    assertEquals("\"error\"", search.getQueryString());
 
     // Check the child is a Relation
     assertTrue(search.getChild().get(0) instanceof Relation);