LDA doc: Add warning about losing backwards compatibility
diff --git a/src/ports/postgres/modules/lda/lda.sql_in b/src/ports/postgres/modules/lda/lda.sql_in
index 883c478..05ad887 100644
--- a/src/ports/postgres/modules/lda/lda.sql_in
+++ b/src/ports/postgres/modules/lda/lda.sql_in
@@ -30,6 +30,10 @@
@brief Generates a Latent Dirichlet Allocation predictive model for a collection of documents.
+@warning Due to change in internal structure of an LDA model in v1.8, model tables
+computed by MADlib versions prior to v1.8 cannot be used with the v1.8 prediction function.
+
+<hr>
Latent Dirichlet Allocation (LDA) is an interesting generative probabilistic
model for natural texts and has received a lot of attention in recent years.
