gate behind planetscale feature flag

Cargo.toml

@@ -53,6 +53,7 @@ discovery = ["futures", "parser"]
 parser = ["query"]
 query = ["def"]
 writer = ["def"]
+planetscale = []
 probe = ["query"]
 sqlx-dep = ["sqlx"]
 sqlx-all = ["sqlx-mysql", "sqlx-postgres", "sqlx-sqlite"]

src/mysql/def/index.rs

@@ -54,6 +54,7 @@ pub enum IndexType {
     RTree,
     #[iden = "SPATIAL"]
     Spatial,
+    #[cfg(feature = "planetscale")]
     #[iden = "VECTOR"]
     Vector,
 }

src/mysql/writer/index.rs

@@ -52,6 +52,7 @@ impl IndexInfo {
                     self.idx_type.to_string(),
                 ))));
             }
+            #[cfg(feature = "planetscale")]
             IndexType::Vector => {
                 index.index_type(sea_query::IndexType::Custom(SeaRc::new(Alias::new(
                     self.idx_type.to_string(),